This paper focuses on graduated autonomy in the context of genetic testing during adolescence. Questions can be raised about other life stages as well, and some of these questions will be addressed by discussing a possible fourth characteristic of graduated autonomy, that is, its elasticity. Further scholarship and analysis is needed to refine the concept of graduated autonomy and examine its applications.Autonomy takes many shapes. The concept of “graduated autonomy” is conceived as comprising several unique features: (1) it is incremental, (2) it is proportional, and (3) it is related to the “There is no steady. . . progress in this life; we do not advance through fixed gradations, and at the last one pause throughinfancy’s unconscious spell, boyhood’s thoughtless faith, adolescence’ doubt (the common doom), then skepticism, thendisbelief, resting at last in manhood’s pondering repose of If. But once gone through, we trace the round again; and areinfants, boys, and men, and Ifs eternally. Where lies the final harbor, whence we unmoor no more?”Herman Melville Spinning, weaving, and severing the threads of life, three divine sisters known as “the Fates” were held accountable for human destiny in the era of Greek mythology. Millennia later, in the era of chromosome testing, we are still learning how genetic fibers contribute to life's intricate tapestry. Patterns, of course, are not determined by threads alone. To a greater or lesser degree, we exercise autonomy and assume moral responsibility for choosing our goals and charting our course. We can even decide how familiar we want to become, through DNA testing, with our own genetic material.Autonomy is a means of inspiring choice and guiding decisions, but it is not, I submit, an all-or-nothing proposition. Drawing upon various developmental theories, this paper introduces the concept of graduated autonomy, identifies its core elements, and explores its application to adolescent genetic testing. It then reviews genetic testing recommendations by various professional and political bodies and compares them for consistency with criteria for graduated autonomy.Three preliminary observations are in order. First, this discussion is limited to genetic testing and does not embrace genetic research or genomic therapy. Second, issues of genetic testing, autonomy, and children's rights are global in scope. Principles, position papers, and pronouncements have been issued by national, supranational, and international agencies including the American Pediatric Society, the European Union, and the United Nations. Third, it should not be assumed that exercising autonomy always leads to action. To the contrary, the decision to refrain from genetic testing or avoid learning its results can involve the same degree of autonomy as the decision to undertake testing and embrace its outcome. “Autonomy includes both the right to know and the right not to know one's genetic status” . In an iIn order to take a “graduated” approach to autonomy, we must try to understand what the term autonomy means in the first place. Derived from the Greek “auto” (self) and “nomos” (law), autonomy has been defined succinctly as self-governance. This does not answer the question, however, of whether autonomy is a state of being, or a process, or both.When I reach maturity, I attain autonomy.” From this perspective, autonomy is a state of being. Autonomy in adolescence is not necessarily a unitary concept, however [Autonomy has been described as the ability to regulate one's own behavior . One mig however . Accordi however . Various however . From thAs I mature through my teen-age years, I become more autonomous.” During adolescence, the task of “becoming” autonomous involves distancing and individuating from one's parents and taking responsibility for oneself. This does not necessarily require severing familial ties, but renegotiating them. “Once regarded as the process of striving to gain freedom from one's parents, autonomy… is now understood as an interpersonal process by which the adolescent begins to develop a greater capacity for independent behavior in the context of continued family connections” [From other perspectives, autonomy is a dynamic, adaptive work-in-progress, for example, “ections” . In broaections” . “(I)n cections” .or as a process, autonomy concerns our relational dimension. There is both freedom from an “other” and freedom to express the “self.” As observed by Soenens and colleagues, adolescent autonomy encompasses two separate (but often simultaneous) phenomena: separation and individuation from parents and self-actualization or “self-determination” [In both iterations, as a state of being ination” . The forination” . In termination” .telos) where graduated autonomy is being engaged.A third view of autonomy might regard it as neither a static condition nor a fluid process, but rather as a competency. In this sense, autonomy can be likened to a tool or a skillset, which can be “disaggregated” into cognitive, emotional, and behavioral features . The seeonly time during a life cycle when autonomy develops. Indeed, one thesis of this paper is that autonomy during adolescence can properly be viewed as a substrate of graduated autonomy throughout life.It has long been acknowledged that becoming autonomous is a central developmental task for adolescents . This isFrom a developmental perspective, human growth moves through sequential phases of cognitive, emotional, behavioral, and moral awareness during childhood and adolescence. Piaget, Kohlberg, Gilligan, and Erikson have all contributed to our understanding of character formation during life's first two decades. The persistent challenge has been that a linear conception of these phases does not completely explain the uneven rate at which adolescents move through them.In the realm of genetic research, concepts of assent and joint decision-making have been adopted to fill in the gaps. As Miller and Nelson explain “Joint decision-making between parents and children typically precedes full decision-making autonomy during adolescence… A developmental approach to assent would respect that shared decision-making between parents and children is a characteristic of normal development” .From the standpoint of adolescent psychodynamics, there may be at least one critical difference between genetic research and genetic testing. Testing is directed at the personal architecture of an individual subject, whereas research focuses on a larger demographic wall in which the individual subject is merely one brick. Vulnerability may be experienced much differently during testing than it is during research, and yet again differently depending upon whether testing arises from individual or family motivations. In either case, vulnerability is a cornerstone principle in European bioethics and its implications for genetic testing invite further scrutiny.Assent in the context of genetic research and graduated autonomy in the realm of genetic testing share several common elements. First, assent is premised (in part) on assumptions that today's assenting minor is likely to become tomorrow's consenting adult.“(S)olicitation of assent from minors engages them in graduated levels of decision-making, in which they participate in developmentally appropriate ways. Assent thus serves as a “learner”s permit' for decision-making, enabling adolescents to gradually assume independence so that full decision-making autonomy is not exercised until they have some experience with the task” .In this regard, assent and graduated autonomy both operate on a continuum, reflecting a common incremental approach.In the second place, assent is tinged with proportionality. In a thoughtful discussion of relationships between physicians and their younger patients, the American Pediatric Association observes that assent can “empower children to the extent of their capacity” and counsels pediatricians to “give serious consideration to each patient's developing capacities for participating in decision-making, including rationality and autonomy” .In other words, the benefit that minor patients derive from assent is scaled to the degree that they can participate in the process of giving it.or not and can be viewed as a condition during which individual capabilities are crystallizing (or dissolving).Notwithstanding these correlations, however, graduated autonomy (in the context of genetic testing) is not merely the functional equivalent of assent . Assent is a precursor to agreement . Graduatas well as assisted decision-making during advanced years. First visible through the topsoil of childhood, graduated autonomy becomes alloyed with age and maturity. It is melded into one of adulthood's supporting girders, and then as cognitive, emotional, and social layers of selfhood erode, it reappears as a residue of self-hood. Metaphorically, it can be compared to the lifecycle of a mosaic design in which numerous tiles are selected, assembled, cemented, and then worn away over time.When viewed in the larger context of the full human life cycle, graduated autonomy can be conceived as the foundation of assent and joint decision-making during adolescence The broader philosophical, psychiatric, and behavioral implications of graduated autonomy across the age spectrum remain open to debate and examination in future works. For present purposes, we look to the incremental, proportional, and teleological aspects of graduated autonomy within the narrower context of genetic testing decisions for adolescents.In an effort to identify optimum times during teen-age years for exercising autonomy regarding genetic testing, Wehbe and colleagues conducted in-depth interviews of adolescent females at risk for being carriers of fragile X syndrome . The stuResults indicated that first-stage awareness, that is, general awareness about the inherited nature of certain diseases, was regarded as being appropriate to be introduced at younger ages than actual knowledge about carrier status.“The majority of the adolescent and young adults in this study felt that a child should learn that fragile X syndrome is an inherited disorder in early childhood and no later than the preteen years. Participants felt that it was important to learn this information early, often endorsing staging of the information in a developmentally appropriate manner” .According to Wehbe's study, the optimum time for second-stage awareness, that is, the possibility of carrier status, is during preteen and teen-age years.“Study participants felt that it was important for a girl to be old enough to have the necessary level of intellectual maturity to understand the implications of what “being a carrier…” means for future reproduction. Many were concerned that a younger child might not be able to understand this information. Additionally, some participants felt that information regarding risk status should be timed concurrently with physical maturity, expressing concerns for an unplanned pregnancy and/or reproductive decision-making during this time” .As voiced by one participant, the teen-age years are appropriate for disclosure of potential carrier status “because I mean you can actually understand it, and it's more known to you, like, you realize what it means and stuff” .Wehbe's results are consistent with findings among adolescents at risk for carrying other types of genetic disease. Järvinen et al., surveyed young adult women with a family history of Duchenne muscular dystrophy and hemophilia A. They reported that the majority of subjects believed that carrier testing should occur during childhood or teen-age years .On the other hand, some teen-agers prefer to wait until later before knowing results of genetic tests. James and colleagues studied nine adolescent females who each had a sibling affected by chronic granulomatous disease and discovered that “many of these girls felt carrier testing for this disorder should not be offered until 18 years of age or older” .In another study illustrating the incremental features of graduated autonomy, Wray-Lake and colleagues mapped trajectories of autonomous decision-making over ten years in 201 American families . Their fAlthough ages may vary, it remains true that “(f)or children and adolescents, decision-making autonomy develops gradually and involves taking on increased responsibility for making decisions previously made by parents” . All of In the context of graduated autonomy, proportionality means “scaled to life conditions.” For example, research indicates that autonomy occurs differently for adolescents with spina bifida than it does for teenagers without inherited disease, but there is a rough symmetry between the curves. Adolescents with spina bifida, compared to each other, also mature at different rates in proportion to the burdens of their disabilities.These findings came to light when Friedman and colleagues conducted an eight-year longitudinal study of some 68 children and adolescents, ages 9 through 15, who were affected by spina bifida . InvestiResearchers predicted that children affected by spina bifida “would lag behind their peers in autonomy development, starting at a lower level of autonomy and additionally demonstrating a less rapid growth trajectory as they transition into adolescence” . ResultsProportionality in the context of autonomy can also be based on comparative maturity. Speaking on behalf of the European Society for Human Genetics, Borry and colleagues recommend that “in the context of genetic testing, the opinion of minors should be taken into consideration as an increasingly determining factor in proportion to his or her age and degree of maturity” , 16. Acc“There is a huge individual and societal variation regarding the moment when particular levels of competence are achieved. As a consequence from an ethical perspective, a rule about competence that is solely based on age cannot be satisfactory… All children do not develop in the same way. Children of the same age may have a different level of development or maturity. As soon as minors, in proportion to their age and degree of maturity, are able to participate in the decision-making, their opinion should be taken increasingly into consideration” , 16.In effect, Borry et al. recommend that the weight given to an adolescent's opinion about genetic testing should be gauged in proportion to the maturity of the decision-maker. The authors also mention a number of other important factors that should be considered:“When assessing competence, it is important not to assess general competence, but to assess a patient's level of understanding in relation to a specific choice that has to be made. “The nature and complexity of the decision or task, the person's ability to understand, at the time the decision is made, the nature of the decision required, and its implications are all relevant. Thus, the graver the impact of the decisions, the commensurately greater the competence needed to make it” , 16.and the maturity of the patient.In other words, proportionality should consider the type of disease, the gravity of the decision, telos or goal of adolescence is maturity. Hence, as autonomy develops during adolescence, it can be conceived as progressing towards an end, namely, adulthood. In this sense, graduated autonomy in adolescence evolves toward mature autonomy, as youth is driven to age.An additional theoretical basis exists for graduated autonomy, grounded in teleology. In rough terms, the Miller and Nelson suggest that assent is a springboard to full-blown informed consent and is teleological in that sense as well.“Joint decision-making between parents and children typically precedes full decision-making autonomy during adolescence. The concept of joint decision-making… serves as a useful framework from which to understand the way in which child assent can facilitate children's growing autonomy. In addition, this  framework is potentially useful for understanding the process by which adolescents become fully autonomous and capable decision-makers themselves” .not be interpreted to mean that graduated autonomy occurs only during adolescence, however. To the contrary, extrapolating from statistical patterns in their study of 153 Flemish adolescents in Belgium, Soenens, and colleagues concluded that there is an “innate need for autonomy that is essential for optimum functioning across the life span” [This should fe span” .telos of human aging, it incrementally declines. “(T)hroughout life, autonomy advances and declines as individuals develop new competencies and changing conditions require alterations in behavior” [An intuitive basis exists for positing that graduated autonomy (like life itself) could proceed along a parabolic curve, advancing through adolescence into adulthood until, in keeping with the ehavior” .or wane. Another way to frame this corollary is that autonomy can be graduated in either direction.  In this sense, graduated autonomy can be described as “elastic.”It follows, then, that graduated autonomy could wax Empirical evidence of this proposition would be difficult to obtain, and it lies beyond the scope of this paper to design appropriate studies. At this point, it can be said only that the application of graduated autonomy applies to life's ebbs, as well as its flows, bears further attention.Graduated autonomy, particularly with respect to its proportionality component, can be a useful heuristic tool for interpreting international health care compacts about health care rights for younger patients.Article V of the United Nations Convention on the Rights of the Child recognizes that parents and adult caretakers have rights, duties, and responsibilities for furnishing a child with “appropriate” direction and guidance “in a manner consistent with the evolving capacities of the child” . ArticleGraduated autonomy, correlated with proportionality, is also manifest in the European Convention on Human Rights and Biomedicine adopted by the Council of Europe. Article 6 of the Convention relates to the protection of persons (including minors) who are not capable of full informed consent. Paragraph 2 of Article 6 stipulates that “where according to law, a minor does not have the capacity to consent to an intervention… the opinion of the minor shall be taken into consideration as an increasingly determining factor, in proportion to his or her age and degree of maturity” .Another facet of graduated autonomy's heuristic value, when interpreting professional norms, can be found in its incrementalism. The American Academy of Pediatrics has declared that “as children develop, they should gradually become the primary guardians of personal health and the primary partners in medical decision-making, assuming responsibility from their parents” . The incper se, an appetite for identity. For some adolescents, a decision to avoid testing signals their belief that personal identity is not determined by reference to genetic lineage. For others, a choice to undergo testing announces their acceptance of genetic influence. In either case, a decision to test (or not) is a declaration of self-awareness.Given the sensitivity and volatility of family relationships during teen-age years, decisions about genetic testing deserve careful attention. To focus only on test results would overlook a crucial ingredient in the mélange of adolescence: the choice about whether to engage in the act of testing indicates, telos of life stages. Conversations and colloquia involving developmental psychologists, child and adolescent psychiatrists, and genetic counselors can make valuable contributions, along with participation from pediatricians and philosophers.The concept of graduated autonomy is a framework for understanding decisions by adolescents about genetic testing. Considerable research and reflection will be needed to further refine graduated autonomy and its elements of incrementalism, proportionality, elasticity, and correlation to the We walk upon the carpet of the past when approaching the threshold of the future, and many strands of thought entwine with our genetic fibers to weave a tapestry of possibilities. Graduated autonomy, it is hoped, adds a helpful thread to these patterns.


Smallpox was “the most terrible of all the ministers of death,” wrote English historian Thomas Macaulay. In the 17th century, the “small pox was always present,” unlike the plague, which visited on occasion. Before this time, the disease did not pose a serious threat to the English or other nations in Europe perhaps because, as scant available records suggest, less virulent forms of the disease were endemic. In his account of Queen Mary’s death (1694), Macaulay spoke of smallpox as indiscriminate and pernicious, attacking royalty and the poor alike, “turning the babe into a changeling at which the mother shuddered and making the eyes and cheeks of the betrothed maiden objects of horror to the lover.”Early in the century, the disease started appearing in English poetry, and in 1616, the year of Shakespeare’s death, Ben Johnson published “An Epigram to the Smallpox”: “Envious and foule Disease, could there not be / One beauty in an Age, and free from thee?” These writings reflected growing awareness of smallpox as debilitating and deadly. By the end of the century, it had overtaken not only the plague but leprosy and the great pox, syphilis, and was spreading quickly in communities, disrupting the social fabric and causing epidemics similar to those that would sweep the globe in the 18th and 19th centuries. The general belief was that smallpox was carried from the sick on clothes and bedding, though the primary source of infection was actually particles of moisture in the patient’s breath. Infection traveled hundreds of yards by air, and the virus entered the body through the nose and mouth rather than cuts in the skin.Malodorous and disfiguring, smallpox held none of the mystique of tuberculosis, whose wasting febrile victims would later inspire romantic literature, music, and art. On the contrary, it struck fear in the hearts of poets, from Andrew Marvel to John Donne. Those who tried their hand at elegies struggled to align this “loathsome and unlovely” condition with internal beauty. A tribute by a young John Dryden to his friend Lord Hastings, who died the day before he was to marry, illustrates the pitfalls: “Blisters with pride swell’d; which th’row’s flesh did sprout / Like Rose-buds, stuck i’th’ Lily-skin about. / Each little Pimple had a Tear in it, / to wail the fault its rising did commit: / Who, Rebel-like, with their own Lord at strife, / Thus made an Insurrection ’gainst his Life.”Dryden’s attempt in his first published poem to liken Hastings’ pustules to rosebuds and later to gems and stars failed to transform smallpox to anything palatable. Dryden was not alone in confronting the reality of pathologic symptoms in a poem, but this disease, an everyday event, defied metaphorical interpretation and therefore transformative treatment. Moreover, it was not viewed as divine punishment for “Capital offense, / Some high, high Treason.” It remained instead, a “Fierce disease, which knows not how to spare / The young, the great, the knowing, or the Fair.”Records from Glasgow show that in the immediate prevaccination era (1783–1800), 50% of children died before age 10, and of those deaths, 40% were due to smallpox, the leading cause of blindness in Europe. Those who survived were often badly blemished, “Beauty’s Enemy” lingering “in many a pityed face / Those hatefull pits and furrowes of its trace.”The roots of smallpox in antiquity have been argued, as have efforts to control it. The practice of variolation―inoculation with a small amount of material from a pustule or scab of a smallpox patient—had long been known in Asia and was introduced to Europe and North America in the early 1700s. But it was not widely practiced because of the risk for disease or death to the inoculated person and the risk for creating new outbreaks.Then Edward Jenner (1749–1823) came along. An alert physician, he observed that some in his community, mostly farmers and milkmaids frequently exposed to cowpox, did not come down with smallpox. Bucking anecdotal evidence and standard variolation, he went out on a limb. “The first experiment (14 May 1796) was made upon a lad of the name of Phipps, in whose arm a little Vaccine Virus was inserted taken from the hand of a young woman who had been accidentally infected by a cow…. On his being inoculated some months afterwards, it proved that he was secure…. As soon as I could again furnish myself with Virus from the Cow, I made an arrangement for a series of inoculations.”Inquiry into the Causes and Effects of the Variolae Vaccinae, A Disease Discovered in Some of the Western Counties of England, Particularly Gloucestershire, and Known by the Name of the Cow Pox. He submitted this small but potent study for publication in the Philosophical Transactions of the Royal Society of which he was a member recognized for his contributions to the field of natural history. The manuscript was rejected, so he published it himself.Jenner wrote his observations in his vacca (cow), acknowledging the essential link between human and animal health. Eventually, the procedure of injecting the vaccine was generally referred to as vaccination. Louis Pasteur later insisted that all inoculations designed to protect against disease be called vaccinations in honor of Jenner and named his own discovery “rabies vaccine,” though it had no connection with cows.An early practitioner of One Medicine, Jenner referred to the cowpox material as “vaccine,” from the Latin Edward Jenner Vaccinating a Boy, on this month’s cover, commemorates vaccination against smallpox by the country doctor from Berkeley, England, who first demonstrated its effectiveness. Jenner, relying on epidemiologic observations, transformed haphazard efforts against smallpox into a public health approach to disease control and laid the foundation for eradication of this disease and the prevention of many others. This historic moment was captured by Eugène-Ernest Hillemacher, a French painter who worked in the tradition of William Bouguereau and Jean-Léon Gérôme―academic painters known for their affection toward historical subjects. A student of Léon Cogniet, Hillemacher exhibited in the Salon and became Chevalier de la Légion d’Honneur.The artist’s rendition of Jenner’s moment in history carefully recorded it for posterity. This traditional bucolic setting shows a family in their modest country home. The back of a cow sharing the premises is visible behind the crib. The good doctor is fully engaged, comforting the young patient who is about to feel a prick. The parents lean forward trustingly. Ample light and bright colors denote optimism. This family’s future is safe from pestilential illness. But Jenner here is not tending this child alone but all children. He is pioneering public health’s crowning achievement, childhood immunization.While the specter of smallpox did not translate into lyrical verse, the prospect of its relief resonated with poets and artists. Samuel Taylor Coleridge, whose son died after being variolated, was inspired by Jenner’s bold discovery and wrote to him. Eliciting the genius of John Milton, he rated the discovery “capable in the highest degree of being poetically treated,” by the bard’s very definition of poetry as “simple, sensuous, and impassioned.” Coleridge did not follow up, but other Romantic poets did. In 1804, Robert Bloomfield wrote in “Good Tidings or News from the Farm” about the “fragrance of the heifer’s breath.”In the 180 years between Jenner’s earthshaking experiment and the fulfillment of his vision that “the annihilation of the Small Pox… must be the final result of this practice,” he was often berated and ridiculed, particularly for injecting animal material into humans, thus diminishing the distance between them and unclean or sick beasts. We have since learned enough about our close kinship with the animal kingdom, and the dangers involved, to look back at the origins of “vaccine” with affection. Unlike humans whose breath spread smallpox to those who “breath’d the tainted air,” Jenner’s heifer lived in the house with the farm family, sharing nothing but her fragrant breath.


In Study 2 we found that respondents reported having noticed, and having been annoyed by, specific problems in presentations arising from violations of particular psychological principles. Finally, in Study 3 we showed that observers are not highly accurate in recognizing when particular slides violated a specific psychological rule. Furthermore, even when they correctly identified the violation, they often could not explain the nature of the problem. In sum, the psychological foundations for effective slideshow presentation design are neither obvious nor necessarily intuitive, and presentation designers in all fields, from education to business to government, could benefit from explicit instruction in relevant aspects of psychology.Electronic slideshow presentations are often faulted anecdotally, but little empirical work has documented their faults. In Study 1 we found that eight psychological principles are often violated in PowerPoint Indeed, in 2001, Microsoft estimated that an average of 30 million PowerPoint® presentations were given each day – and we can only imagine what that number is today , that some types of presentation flaws will be noticeable and frustrating to audience members (Study 2), and that observers will have difficulties in identifying violations in the case of graphical displays in individual slides (Study 3).In the three studies reported here, we empirically extend ideas presented in Kosslyn , 2010 anLevasseur and Sawyer  note in We acknowledge that the following formulation is but one of several possible ways to organize these guidelines within the conventional view of human information processing, but this one . In what follows, we first present the basic findings about information processing that led us to formulate a specific principle, and then explain the principle and how we operationalized it. Crucially, because all of these principles stem from known bottlenecks in information processing, slideshows, slides, and presentations that violate them will tax human information processing.In formulating our eight Cognitive Communication Principles, we began with a task analysis; that is, we considered what the viewer must do to understand a presentation. This analysis rests on the now-standard view that perception and comprehension can be decomposed into distinct classes of information processing operations , we do not mean to imply that these processes work in lockstep sequence. Rather, by focusing on the operations, we are led to define the bottlenecks that can disrupt presentations.When viewing a sequence of slides, audience members first must encode what they see; if they fail to encode material, it may as well not exist. We formulated three principles based on essential facts about encoding.the Principle of Discriminability: two properties  cannot convey different information unless they differ by a large enough proportion to be easily distinguished Unless typefaces are large enough, letters cannot easily be distinguished from each other.(2)If the color of text or graphics is not clearly distinct from the color of the background on which they appear, they cannot be readily distinguished.(3)Typefaces in which letters are similar  cannot be easily read.(4)Because patterns that are registered by separate “spatial frequency channels” are easily distinguished Similarly, because orientations that differ by at least 30° are processed by different “orientation channels” Finally, because of the way that different wavelengths of light focus on the retina, we have difficulty bringing cobalt blue (which is a mixture of red and blue) into focus, and we have difficulty focusing on red and blue at the same time (combinations of these colors tend to “shimmer”); thus text or other fine lines are difficult to distinguish if they are rendered in deep blues, and boundaries defined by adjacent red and blue regions are distracting.Principle of Perceptual Organization: people automatically organize elements into groups, which they then attend to and remember . This observation leads us to formulate the Grouping also can be imposed by lines, such as those used in complex tables to define specific regions, which makes the tables easier to read. In addition, some visual dimensions are automatically grouped; these dimensions are “integral,” and cannot easily be considered independently. For example, height and width are not easily seen as distinct, but rather are organized into a single shape – and viewers register the overall area, not the two dimensions separately Labels initially are seen as applying to the closest graphic element.(2)Common color organizes parts of a display into a group, even if they are separated in space.(3)Common patterns or orderings organize parts of a display into a group, even if they are separated in space. For example, when the elements in a key  are ordered the same way as the corresponding parts of the display , the elements in the key will be grouped appropriately with the corresponding parts of the display.(4)Y axis at the left of the graph, if specific point values are to be read).Because shape and location largely are processed separately in the visual system Comprehension is impaired by spurious groups, which form accidentally because of the grouping laws .Principle of Salience states: attention is drawn to large perceptible differences. In fact, a part of the brain (the superior colliculus) operates as an attentional reflex, automatically drawing our visual attention to large differences among stimuli . Thus, some units are encoded in detail before others. Attention selects which patterns will be processed in detail, and attention is automatically drawn to what is different; we immediately notice the nail that sticks above the floorboards or the one red light in a group of green lights. The  Posner, . The Pri(1)Because movement is a particularly salient cue Text with a distinct format  draws attention.(3)Visual disparities draw attention. For example, we notice a wedge exploded from a pie chart because the boundary has been disrupted; however, if more than one or two wedges are exploded, the boundary becomes so disrupted that the separated pieces are no longer salient.(4)If salience is aligned with importance A special case of salience arises with colors: because of a quirk in how the corneas diffuse light and project it onto the retinas, “warm” colors  seem closer to the viewer than do “cool” colors The amount of information that people can retain in working memory is defined in terms of psychological units, such as the perceptual groups produced by the classical perceptual grouping laws. We can hold in working memory only about four such units Cowan, . However(2)In general, humans can track the movement of only about four units at the same time Eliminating the need to search for labels – for instance by directly labeling items in a display rather than using a key – reduces processing load Audience members need time to process the information that is presented.(5)However, conversely, if slides fade-in or fade-out very slowly, the audience members may organize them incorrectly and then have to break their initial organization – which also requires effort Potter, .Principle of Informative Change, people expect changes in perceptual properties to carry information, and expect every necessary piece of information to be conveyed by such a perceptible change. Indeed, the very concept of “information” has been defined in terms of change: only when there is a change is information conveyed Audience members assume that words, graphics, or other changes in appearance convey new information Clearly marking the beginnings and ends of sections of a presentation  helps audience members follow the presentation.Our task analysis leads us to posit a third class of relevant processes. Encoding information and integrating it appropriately would be useless if the meaning of the material were not extracted. In order to ascribe meaning to stimuli, one must compare them with material previously stored in long-term memory; it is only by retrieving associated information that we comprehend the import of what we see. The following principles address factors that affect the ease of accessing long-term memory and activating the relevant stored information.Principle of Appropriate Knowledge states: communication requires prior knowledge of relevant concepts, jargon, and symbols. If the presenter relies on novel concepts, jargon, or symbols, the audience members will fail to understand. The Principle of Appropriate Knowledge has the following corollaries:Meaning can be ascribed to a pattern only if the person has the requisite information already stored in long-term memory; to reach an audience, the presenter must make contact with what the audience members already know Unfamiliar (for that audience) concepts, conventions, formats, terminology, and symbols may not be understood. Moreover, when they are understood, they will likely require effortful processing (which will be accomplished only if the audience is highly motivated).(2)If unfamiliar (for that audience) concepts, conventions, formats, terminology, and symbols are absolutely necessary to convey the message, they must be explicitly introduced and explained – and such explanations are more effective if they draw on information that is familiar to the audience.Principle of Compatibility states that a message is easiest to understand if its form is compatible with its meaning  is inconsistent with its symbolic meaning. The  Vessey, . This pr Vessey, . In the (1)Because hue is a metathetic  variable, variations in hue are not seen automatically as signaling different amounts of a quantity; in contrast, because saturation and intensity (or brightness) are prothetic variables , variations along these dimensions do line up with variations in quantities Stevens, .(2)Animation interferes with comprehension if it does not fit the natural movements of the object , and sounds and slide backgrounds will interfere if they are not appropriate for the topic .(3)Viewers most easily interpret icons that depict the typical examples of represented items. For example, a picture of a duck effectively illustrates “water fowl” but not “pet bird,” and vice versa for a picture of a canary Old-fashioned looking typeface would send a conflicting message if used in a written description of a high-tech device.(5)Because they make different sorts of information explicit, different sorts of graphics are appropriate for making different points To decide what is too much or too little, one must know about the nature of the message: depending on what the intended point is, specific information can be necessary or extraneous.(2)When attempting to understand information, people (largely unconsciously) organize it into a narrative Graphics , audio, and video can provide detail to illustrate the relevant concepts clearly. However, pictures are often ambiguous , Education, Government, Business, and Miscellaneous. We formulated 137 ways (each specified in a rule) in which the eight principles just summarized could be violated , we randomly selected slideshows within each category. To this end, we implemented a two-step procedure. We first constructed a list of keywords for each of four categories – Research (academic), Education, Government, and Business – by searching an electronic resource  for the category name and then noting the keywords of the first few academic articles to appear in the search results. We then randomly paired each keyword with two numbers, which ranged from 1 to 10. The first number designated the page, the second the position of the item within a page. For example, a keyword, page, and position combination could have been “marketing, 6, 4.”® slideshows). For example, if the keyword and page combination was “marketing, 6, 4,” the search term would have been “marketing.ppt,” which would yield a series of Google hits from which we would select the forth hit on the sixth page. In cases where the specified hit was not a slideshow, the next slideshow down would be selected, and if that entry was not a slideshow, we looked at the subsequent one, repeating this process until we found a slideshow. The minimum required length for slideshows was 15 slides, and the maximum allowed length was 100 slides; if slideshows contained fewer than 15 or more than 100 slides, we again selected the next slideshow in the list until we found a slideshow of suitable length.We then performed each search by entering the keyword followed by a space and then “.ppt” . Because we selected search terms that were targeted for a specific category, we were likely to find slideshows in that category – but our search method did not guarantee this result, and thus we double-checked the appropriate category after each slideshow was retrieved. Our search methods were designed to have a high probability of sampling from the different categories, and we had hoped to sample about the same number of slideshows from each category. However, our criteria were not perfect, and thus the numbers in each category are not precisely the same. Ultimately each category contained between 20 and 40 slideshows, specifically: Research: 27, Education: 38, Government: 20, Business: 32, and Miscellaneous: 23.®, and we worried that Keynote® users might also represent a biased sample. Thus, we can only be confident that our results generalize to PowerPoint® slideshows per se. In addition, because we sampled from the web, our results can only generalize to other slideshows of the sort that are posted on the web .We note that we did not search for “.pptx” or “.key” or for other extensions. At the time the study was begun (2008), .pptx had not been available very long – and hence we worried about possible biases of sampling works from “early adopters.” In addition, the vast majority of slideshows are created with PowerPointFour judges scored the 140 slideshows for violations of the 137 rules. Two of the judges were authors, and two were college-educated paid research assistants in the laboratory; at the time of coding, none of the judges knew whether or not they would subsequently do enough work on this project to be included as authors, and none were biased to find flaws . Each rule was worded as a statement that, if it described a slide or slideshow as a whole, revealed a violation of that rule.Two of the judges began by independently scoring 10 slideshows, and then comparing their scores. Any disparities were discussed, and in five cases the wording of rules was modified to be more specific. Following this initial training and calibration procedure, each judge independently scored all of the slideshows. The judges then discussed any disparities in classification or scoring, and reached a consensus.The initial two judges interpreted each rule literally (“strictly”). For example, if the rule stated that no more than two lines should be included in a single bullet point, then a bullet point that had two lines and a single word in a third line would be classified as violating the rule. We adopted this procedure because we wanted to be sure that the rules could be easily interpreted. Nevertheless, we were concerned that we would inflate the number of violations by adhering rigidly to the rules; many of them were intended to be heuristics. For example, the prohibition against more than two lines per bullet point is based on the idea that no more than four concepts should be held in working memory at the same time, and in general two lines of text convey about four concepts.Thus, following the initial scoring, two additional judges considered each of the violations identified by the first two judges. They decided, independently, whether each violation was important. In this case, “important” was defined as “likely to disrupt the comprehension or memory of the material.” If not, then they rejected that initial classification of a violation. By using both the strict and liberal scoring methods, we thereby defined a range in which we evaluated the slideshows. Table The dependent variable was whether or not a slideshow violated a principle. We took a “bad-apple-spoils-the-barrel” approach: if even a single slide contained material that violated a rule, the slideshow was scored as having violated the rule. And if a slideshow violated one or more rules within a specific principle, the score for that principle would be “1;” if none of the rules were violated for a principle, the score for it would be “0.” We present first the results from the strict, initial scoring, and after this the results from the more liberal scoring.We began by assessing inter-rater reliability. The overall inter-rater agreement was 0.88, which indicates the proportion of times that the raters either both coded “1,” indicating a violation, or both coded “0,” indicating no violation. We then sought to answer three questions about the data.F = 2.24, p > 0.05, First, we asked whether the violations of the principles differed for the different categories  = 87.94, p < 0.01, post hoc test with an alpha of 0.05 revealed that out of the 36 possible comparisons, only the following eight were not significant: the difference between Appropriate Knowledge and Salience, Compatibility and Over-determined, Compatibility and Perceptual Organization, Discriminability and Limited Capacity, Informative Change and Relevance, Informative Change and Salience, Over-determined and Perceptual Organization, and Relevance and Salience. All other comparisons were significant.Second, we asked whether some principles were violated more frequently than others. As illustrated in Figure F = 1.91, p < 0.05, post hoc procedure documented that the difference in violations between the principle of Appropriate Knowledge and the principle of Compatibility was significantly different between the categories of Research and Government, F = 10.19, p < 0.01, In addition, the results of this analysis showed there was an interaction between Principles and Category, In general, the following aspects of these results are worth noting: the principles of Discriminability and Limited Capacity were violated in every single slideshow, and the principle of Informative Change was violated in 93% of the slideshows. In contrast, the principle of Compatibility was violated in only 31% of the slideshows.F = 1.51, p > 0.05, Third, we examined which rules were violated most often. In particular, we found that the following five rules were violated most often: (1) Bulleted items are not presented individually, growing the list from the top to the bottom (96% of the slideshows); (2) More than two lines are used per bulleted sentence (91%); 3) More than four bulleted items appear in a single list (91%); (4) Hierarchical organization of lists is not used, with no more than four items at each level (86%); (5) All uppercase, all italics, or all bold typefaces are used (81%). To examine this result more carefully, we examined whether the five worst rules were violated equally often for the different categories of slideshows. The results showed no interaction between Category and the violation of the five worst rules,  More thaWe again assessed inter-rater reliability, now based on the judgments with the more liberal criteria. The proportion agreement between the two raters for all principles and scales combined was 0.98. The shift from strict to liberal criteria did not change the pattern of the results. Using the new criteria resulted in our eliminating only 4% of the violations that were identified using the strict scoring procedure.F = 1.93, p > 0.1, Considering again our three questions about the data: first, as with the strict coding, we conducted a repeated-measures ANOVA, with the nine levels of the Principles, as a within-participant variable, and Category as a between-participant variable. The results showed that, in general, there were no differences in violations between the categories, F = 79.52, p < 0.05, post hoc test with an alpha of 0.05 showed that out of the 36 possible comparisons, only the following eight were not significant: the difference between Appropriate Knowledge and Salience, Compatibility and Over-determined, Compatibility and Perceptual Organization, Discriminability and Limited Capacity, Informative Change and Relevance, Informative Change and Salience, Over-determined and Perceptual Organization, and between Relevance and Salience. All other comparisons were significant.Second, we again asked whether some principles were violated more often than others. As illustrated in Figure F = 1.44, p > 0.05, As before, the principles of Discriminability (98%), Limited Capacity (100%), and Informative Change (86%) each were violated in the vast majority of slideshows. Also as before, the principle of Compatibility was violated least-frequently, in “only” about a quarter of the slideshows (27%) in this case. The results of the analysis also showed that there was no interaction between Category and Principle, F = 2.35, p < 0.05, post hoc procedure showed that the difference in violations between the rule “Words are not large enough  to be easily seen” and the rule “More than two lines are used per bulleted sentence” was significantly different between the categories of Business and Government, F = 10.99, p < 0.01, Third, we again examined which rules were violated most often. In this analysis, we found that the following five rules were violated most often: (1) Bulleted items are not presented individually, growing the list from the top to the bottom (94% of the slideshows); (2) More than four bulleted items appear in a single list (88%); (3) More than two lines are used per bulleted sentence (87%); (4) Hierarchical organization of lists is not used, with no more than four items at each level (84%); (5) Words are not large enough  to be easily seen (65%). The first four rules are the same as the first four identified in the previous analysis, but now the rule “All uppercase, all italics, or all bold typefaces are used” was replaced by another rule that also stemmed from the principle of Discriminability, namely the rule regarding size. To examine this result more carefully, we examined whether there was an interaction between the five worst rules and categories, and found such an interaction, Table As is clear, by either the strict or liberal scoring criteria, many slideshows are flawed. Indeed, not a single slideshow was scored – according to either set of criteria – as having no flaws. Using the strict criteria, each slideshow violated on average 6.23 of the nine classes of principles, which shrank slightly to 5.88 using the liberal criteria. Considering just the eight individual principles, excluding the “over-determined” group of rules, the overall violation was 6.17 for the strict coding and 5.86 for the liberal coding. The three most-violated principles were Discriminability , Limited Capacity (because too much information was presented), and Informative Change . Even the least-frequently violated principle, Compatibility, was still violated in at least a quarter of the slideshows.In addition, the fact that violations were comparable across the different categories is of interest. We examined the different categories partly in an effort to consider the possible influence of different topics. Although slideshows of different topics (or areas) may differ in their average complexity, the results do not suggest that violations of specific principles generally vary for different topics. That said, we did find that some specific rules were violated more frequently in some categories than others, which could reflect differences in the complexities of the topics.In sum, the present results suggest that the psychological principles either are not obvious or are obvious but often ignored.® slideshows in Study 1 revealed that slideshows themselves typically are flawed in multiple ways. We wanted to know whether viewers are sensitive to presentation flaws more generally, and thus we conducted a survey asking participants to report approximately how many electronic slideshow presentations they had seen in the past year, and then to rate various aspects of those presentations in terms of their quality.The analysis of PowerPoint®, Keynote®, or other electronic slideshows. (In order to receive compensation – either a $5 gift certificate to Amazon.com or a free book – they had to be US citizens or permanent residents and not employed by Harvard University.) All participants provided their informed consent and were tested in accordance with the ethical guidelines of the American Psychological Association; this research was approved by the Harvard University Committee on the Use of Human Subjects.We recruited 265 participants via ads on Craigslist and by word-of-mouth. In order to participate in the study, participants had to be at least 18 years old, speak fluent English, and “regularly” attend presentations that involved PowerPointForty-six of the participants did not meet the eligibility criteria of viewing at least one presentation per month during the previous year, and 14 skipped more than 20% of the questions. Therefore, analyses were conducted on data from the 205 eligible participants who completed at least 80% of the survey, including 112 females (mean age 32.5 ± 8.9) and 83 males (mean age 30.9 ± 8.9) and 10 who did not report their sex or age. According to self-report, about 7% of the participants were engineers, 10% were in finance, 13% were business managers or executives, and 14% were students; the remaining participants were distributed across a variety of different occupations.Surveymonkey.com. The opening page of the survey consisted of a statement about the eligibility requirements and a description of the study content. Participants were assured that their data would be collected anonymously, and that they would be sent to another unrelated survey in order to provide the personal information  we needed in order to send the gift certificate.The study was administered over the internet via a secured link (SSL) on The survey began by asking approximately how many electronic slideshow presentations the participant viewed each year (up to “5 or more per week”). The main portion of the survey consisted of a series of questions about electronic slideshow presentations viewed in the last year. We asked two sorts of questions. First, we asked about the presence of specific problems; for example, we asked “Did any of the presentations fail to convey a meaningful message because there was no main point?” and “Were any of the presentations hard to follow because the slides contained too much material to absorb before the next slide was presented?” Participants were asked to indicate the proportion of presentations – if any – that had such problems, using the following scale: “None (of the presentations); Some; Half; Many; Virtually all.” Second, we asked questions about annoyance, querying the degree to which the problem, if present, bothered them; these responses used a four-point scale, labeled as follows: “Not at all; Somewhat; A fair amount; It was extremely annoying to have my time wasted in this fashion.” It could be argued that by focusing on problems, rather than framing the questions in a neutral fashion, we were biasing the participants to make negative responses – and this is a possible limitation of the survey. However, it is easier, grammatically and logistically, to ask people to notice problems than to notice things that were flawless. If a presentation is excellent the audience will be focused on the presenter’s message, not on the technicalities of the presentation.and any techniques that they thought contributed to especially effective presentations. The final portion of the survey asked for basic demographic information, including age, sex, and occupation .The questions covered typical violations of seven of the eight principles. Because we were asking for overall impressions across all presentations recalled from the past year, rather than analyses of specific slides, we did not ask any questions about Perceptual Organization, fearing that participants would not be able to recall these types of details accurately. We included 12 questions about Relevance; 8 about Appropriate Knowledge; 4 about Salience; 5 about Discriminability; 3 about Compatibility; 2 about Informative Change; 7 about Limited Capacity; and one that did not clearly fit into any of these categories, “Were any of the speakers unprepared in that they didn’t know how to use their technology ?” We also included “free response” questions, asking participants to report any other common problems The Appendix presents a table with all of the questions, the average ratings, and the percent responses in each category of the rating scale, for both prevalence and annoyance. The five items with the highest ratings (bold and underlined) and the five with the lowest  for Prevalence and Annoyance are highlighted in gray. Note that one of the most prevalent violations (lack of a pointer) was one of the least annoying.We coded the data in two ways. First, we converted the five “prevalence of violation” and four “annoyance” ratings into numerical values , and then for each participant we calculated the average rating for prevalence of violations and for associated annoyance level for each principle. Because the most common answers were “none” and “some,” we also coded the data using a binary coding system, coding any degree of violation  as “1,” and “none” as “0,” and any degree of annoyance  as “1,” and “not at all” as “0,” and then again for each participant calculated an average score for both prevalence and annoyance for each of the principles. (The fact that these were the most common answers suggests that participants were not biased by our questions.)p < 0.0005, epsilon > 0.75), therefore degrees of freedom were corrected using Huynh–Feldt estimates of sphericity. The results were similar regardless of the coding used , revealing that some of the principles were violated more often than others, F = 10.80, p < 0.0005, F = 8.00, p < 0.0005, As in Study 1, we asked whether some principles were violated more often than others, calculating one-way repeated-measures ANOVAs. For all ANOVAs Mauchly’s test indicated that the assumption of sphericity had been violated  = 5.15, p < 0.0005, F = 3.05, p < 0.05, We also asked whether violations of some principles were more annoying than violations of other principles.  One-way repeated-measures ANOVAs revealed that violations of some principles were more annoying than others F.9, 968 =Although we did document a significant difference in reported prevalence and annoyance for the violations of different principles, it was relatively small and the most interesting results may be in the responses to individual questions. The three most prevalent problems were also among the five most annoying: “Speakers read word-for-word from notes or from the slides themselves” , “The slides contained too much material to absorb before the next slide was presented” (Limited Capacity), and , “The main point was obscured by lots of irrelevant detail” (Relevance).Because different numbers of questions were asked for different principles, we conducted correlation analyses to discover whether the mean ratings were related to the number of questions per principle. No significant correlations were found between prevalence or annoyance ratings and the number of questions per principle, nor were prevalence and annoyance significantly correlated with each other.We also invited the participants to make free responses about presentation problems that were not covered in the survey, and to indicate key aspects of especially good presentations. These free responses, in general, tended to reiterate topics covered in the survey, for instance, “When explaining complicated information, it’s important to use as many slides as necessary. Do not try and cram it all together.” Or, “a little humor goes a long way.” However, many respondents complained that speakers should be better prepared, by “rehearsing their lectures so they don’t look like it’s the first time they’re seeing these slides too,” and by “hav(ing) everything ready and working properly before (the audience) show(s) up” and coordinating carefully with any assistants who operate the equipment so that technical problems do not derail the entire talk.  In short, “Don’t waste my time! If you aren’t going to properly prepare just send me a memo with information instead!”These results converge with those from the Study 1, namely that all seven principles we asked about (out of eight considered in the first study) are violated on a regular basis. Such violations bother audience members to some extent. And as with Study 1, violations of the Principle of Compatibility were least common, whereas one of the most annoying and prevalent violations fell under the principle of Limited Capacity . These results show that presentations not only have much room for improvement, as shown in Study 1, but also that audience members are sensitive to the general sorts of problems that plague presentations.The findings from Study 1 and Study 2 thus raise an interesting question: why do at least some people feel that the psychological principles are so obvious that nobody would violate them? Is it possible that although people recognize overall problems – such as that a presentation is boring or unclear – they fail to recognize the precise problems with specific slides that produce such easily noticed flaws? We investigate this possibility in the following study.why a display is defective.The present study was designed to answer two questions: first, we wanted to know whether people can identify graphical displays in individual slides in which the different principles have been violated. Second, if they can identify such defective displays, we wanted to know whether participants are aware of The previous two studies were surveys. Such studies have the advantage of tapping into phenomena that occur in the “real world,” but the disadvantage of not having rigorous control over the relevant variables. Study 3 relies on an experiment. We selected a subset of the visual display design rules from Study 1, and prepared two illustrations for each one: one illustration included a violation of the rule and one did not  and 27 females with a mean age of 23.6 (SD = 5.3). Participants were recruited through a Harvard University study pool, which was open to Harvard affiliates and members of the Cambridge/Boston community. None of the participants had prior knowledge of the presented material. All participants provided their informed consent and were tested in accordance with the ethical guidelines of the American Psychological Association; this research was approved by the Harvard University Committee on the Use of Human Subjects.Forty-one “Do/Don’t” pairs of illustrations from Kosslyn  formed tIn addition, we prepared a question for each pair of illustrations. Each question asked participants to choose a panel (left or right) of the pair according to a particular criterion, such as: “Which slide does a better job of using textures?”We tested groups of 3–10 participants together. Participants met in a computer lab, and each was seated at his or her own computer . We administered each of the four sets of stimuli equally often, and thus counterbalanced for presentation order (left/right and forward/reverse).On each trial, participants first viewed the question and then the accompanying pair of illustrations. Participants indicated each choice by typing their answer (“l” or “r”) in a column in a spreadsheet. After choosing, the participants typed a brief explanation of their choice. The participants viewed the questions and pairs of stimuli at their own pace. We include examples of participant responses below, in addition to Figure For instance, we asked the question, “which slide does a better job using the key (the labeled squares at the top)?” The same bar graph was used in both slides. The better slide ordered the patches (squares) in the key to correspond with the order of the bars on the graph (which had the darkest bar in the middle); the flawed slide ordered the patches from lightest to darkest. A correct explanation for selecting the correct slide (matching order) was, “the key is laid out in the same sequence as the bars on the graph.” An incorrect explanation for selecting the correct slide (matching order) was, “the patterns in the key are arranged more dynamically with better contrast.” A completely incorrect response was to choose the non-matching order “because the key feels more orderly, the lightest shade on top and the darkest shade on the bottom.”On another trial we asked, “Which slide uses the background pattern more effectively?” The two slides contained identical captioned and labeled line graphs with home prices over time; both had a photo of a house in the background. In the flawed slide, the background photo was inappropriately pronounced, making the graph difficult to read. The better slide used the same photo, but as a de-saturated watermark; it was visually interesting without in any way obscuring the graph. A correct explanation for selecting the correct slide  was, “[the background] is subtle but nice and doesn’t overshadow the graph.” An incorrect explanation for the correct slide  was, “it is more explanatory.” A completely incorrect response was to choose the slide with the too-salient background because, “you can see all of the beautiful scenery behind the home as well as the attractiveness of its surroundings.”slide choice and for explanation. Two judges  independently scored the explanations participants provided for each of their choices. These judges determined whether the participant had in fact identified the key feature that distinguished the versions of the illustration. We used “liberal” criteria, giving the participants the benefit of the doubt if there were any questions about their accuracy. Inter-rater agreement for the two judges was substantial, at 0.90 . When the judges disagreed in their initial scoring, they discussed the item in question and came to a consensus agreement. Table Because we asked the participants not only to choose one member from each pair, but also to explain their choice, we computed two types of scores: the error rate for F = 22.60, p < 0.0005, The mean error rate for slide choice was 20.5% (with chance performance at 50% errors). A repeated-measures ANOVA revealed that the error rates for slide choice varied for the different principles, F7, 29 = 22.6X axis (Compatibility); use different colors only for emphasis or to specify different classes of information (Informative Change); use a scatterplot to convey an overall impression of the relationship between two variables (Compatibility); use one color for titles and another, less salient one for text .The five stimulus pairs that induced the most errors in slide choice illustrated the following rules: explode a max of 25% of wedges in a pie ; use a line graph to display interactions over two entities on the F = 3.47, p = 0.003, p < 0.0005, epsilon = 0.847, therefore degrees of freedom were corrected using Huynh–Feldt estimates of sphericity.) The participants made relatively more errors when explaining violations of the principles of Discriminability and Informative Change, and were relatively accurate when explaining their choices for the principle of Appropriate Knowledge. Participants had the most difficulty explaining their (correct) choices for displays that illustrated the following rules: avoid using red and blue in adjacent regions (Discriminability); use hierarchical labeling (Limited Capacity); ensure that shapes of meaningful regions are easily identifiable (Discriminability); use one color for titles and another, less salient one for text ; graph different types of data in a single display only if they are highly related and must be compared (Relevance).Although the participants chose the correct alternative on about 80% of the trials, on fully one sixth of these trials, they could not articulate why they made these choices; that is, 16.8% of the explanations for correct choices were incorrect. Thus, for only about two thirds of the total trials did they choose correctly on the basis of knowledge. A repeated-measures ANOVA showed that the participants made more errors for some principles than others when explaining their choices, at least one error in slide choice per principle, and (given they made the correct slide choice) at least one error in explanation per principle; note that there are no principles for which there are no errors.Finally, Table In short, even when guided to pay attention to specific features of slides, observers do not always understand when the psychological principles have been violated, and even when they do realize that there is a problem, they often are not aware of the nature of this problem. Given the way information processing works in the brain, however, one could argue that even if viewers do not notice a violation, they could still be affected by it. Indeed, we would predict this to be the case, and it is well worth investigating this hypothesis in future research.® slideshows, slides, and presentations respect principles of human perception, memory, and comprehension. Specifically, we hypothesized and found that the psychological principles are often violated in PowerPoint® slideshows across different fields (Study 1), that some types of presentation flaws are noticeable and annoying to audience members (Study 2), and that observers have difficulty identifying many violations in graphical displays in individual slides (Study 3). These studies converge in painting the following picture: PowerPoint® presentations are commonly flawed; some types of flaws are more common than others; flaws are not isolated to one domain or context; and, although some types of flaws annoy the audience, flaws at the level of slide design are not always obvious to an untrained observer . Specifically, in Study 1 we found that PowerPoint® slideshows on average violate approximately six of the eight principles we considered. Moreover, this is true for slideshows produced in different fields. The principles of Discriminability, Limited Capacity, and Informative Change were most frequently violated. In Study 2 we found that respondents commonly reported having noticed and been annoyed by problems in presentations in general, and these problems arose from violations of most of the principles we considered. Finally, in Study 3 we showed that observers often did not recognize when a specific rule was violated in a given slide, and that even when they did select the slide without the violation, they often could not explain their choice.In the three studies reported here, we analyzed how well PowerPointBut can we be confident that violations of our principles really constitute “flaws” in a presentation? As noted in the Introduction, our principles grow out of a straightforward task analysis, which in turn led us to consider basic findings in the scientific literature on human perception, memory, and comprehension. Because of this connection, the principles have face validity: if a presentation violates a principle, it taxes human information processing. And because the presentation taxes information processing, the audience members will have difficulty perceiving, remembering, or comprehending it – and hence, it can reasonably be said to be flawed.Nevertheless, future studies should explicitly examine the effects of violating specific principles on comprehension and subsequent memory. Such studies should also assess the degree to which audience members enjoy presentations with specific flaws, and their ability to think critically about such presentations (both while they are underway and subsequently). In addition, future studies should address whether specific types of violations have the same effects for slideshows that are presented versus for slideshows that are posted or distributed (and hence meant to be understood independently of a presenter).By the same token, one could ask whether the rules “measure what they are supposed to measure.” To be clear: the rules do not “measure” anything; we are not presenting a new psychometric instrument. The rules are guidelines that should be obeyed to avoid including characteristics that will impair information processing. In the current research, we devised rules to capture key characteristics that would make presentations difficult to perceive, remember, or comprehend. As such, the “psychometric properties” associated with such a checklist are inherently different from a formal psychological test. For example, the fact that a specific rule is violated by every single presentation is, in the current study, very informative – whereas this is not true for an item in a conventional psychological test.It is worth noting that respecting the principles and rules we have described will not produce “optimal” presentations. Instead, respecting the principles and rules will ensure that presentations are not flawed in these specific ways. Simply avoiding the glitches that we document will not ensure that the presentation is good, but including such glitches will make a presentation bad (or at least not as good as it could be). Given that the principles and rules are rooted in the empirical literature, avoiding violating them will improve a presentation. .We also must point out that in two of the three studies reported here, we treated the slides independently of the presenter. One could argue that at least some of the potential “flaws” may not be as severe when the slides are discussed by a skilled presenter. For instance, a talented presenter may be able to compensate for a particular flaw . However, all else being equal, there is no advantage – and considerable disadvantage – to showing flawed slides. Although some flaws may be compensated for by talented presenters, it would be better if they did not have to compensate in the first place.In short, we have documented that there is plenty of room for improvement in the design of electronic slideshow presentations. The psychological principles apparently are not entirely obvious, nor do people always respect them instinctively. Perhaps the best way to avoid such flaws is to prepare a slideshow draft, review each slide according to the psychological principles and rules we describe here, and then correct flaws as they are detected. Presenters may also want to review the Appendix in order to avoid common presentation mistakes, particularly those that the audience reports as highly annoying. It is worth noting that presentation techniques designed to compensate for poorly designed slides , may sometimes backfire – causing the audience to lose interest and tune out. Making your audience do unnecessary work is not a recipe for a successful presentation.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Imagine you must wrap a present—from the inside. You (as the “gift”) must first cover yourself with one or more sheets of light tissue paper, to keep from getting smudged or rattling around. Next, without leaving or tearing this papery cocoon, you must construct a rugged box to encase both gift and tissue, to protect against mishaps and external onslaughts. Finally, from deep within, using no tools that would damage or mar these previous bits of handiwork, you must overlay the whole parcel with a thin film of wrapping paper, colorfully patterned on its outer side but plain on its inner. If you are even more exuberant you may add ribbons, bows, and baubles to spruce up the completed package, but all the while you must remain embedded at center of these nested shells.Pretty impressive trick, huh?PLOS GeneticsThis lighthearted metaphor describes something very close to what gram-negative bacteria do on a moment-to-moment basis as they create the envelope that surrounds and defends them. The cytoplasm (the “gift”) is surrounded by the inner membrane (the “tissue paper”), the peptidoglycan cell wall (the “box”), and the outer membrane (the “wrapping paper”) see . In trutEscherichia coliTo date, investigators have pieced together the major mechanisms by which each envelope subcomponent is synthesized and directed to one of four destinations  see . ProteinE. coli cells form white colonies on plates containing this compound because CPRG cannot enter intact bacteria. However, cells with an impaired envelope may admit CPRG to the cytoplasm, where the LacZ protein hydrolyzes it to form a red product. Alternatively, if the mutants lyse, LacZ is released into the medium to contact CPRG  gene lysed as they approached stationary phase, a transition point whose regulation is poorly understood. This phenotype was suppressed by overexpressing enzymes involved in the synthesis of peptidoglycan or undecaprenyl pyrophosphate, this latter a critical isoprenoid that participates in the biosynthesis of several envelope components elyC-associated lethality. Thus, characterizing the behavior and genetic interactions of this single mutation has already identified a web of new envelope relationships. More are expected, since the technique allows investigators to bring a whole pantheon of genetic tools to bear on these questions, and because the screen can be adapted to organisms whose envelopes are even less well understood.When Paradis-Bleau et al. tested a library of random transposon insertions and an ordered set of gene deletions in not leak under these or other conditions, thereby expanding the screen's genetic reach. Thus, even its limitations presage the expansion of the technique for use in broader contexts. Of course, even such a significant advance does not solve all problems. First, the technique identifies only those mutants that are viable and that disable the envelope so that it leaks. Mutations that kill cells outright will not appear, nor will mutations that alter assembly without affecting envelope permeability. Second, the screen will probably return mutants that die or leak even if the affected processes have no direct bearing on the envelope (though these may be interesting in their own right). Third, there is an odd temperature limitation: the screen works well at 25°C, but a large background appears when cells are incubated at 37°C. The reason is not clear, but this, too, might be turned into a positive by inverting the approach to look for mutants that do In short, Paradis-Bleau et al. have performed a valuable service by developing this new tool for investigating the complexities of the bacterial cell envelope. And that's a gift for all of us, wrapped just right.