Information and communication technology solutions have the potential to support active and healthy aging and improve monitoring and treatment outcomes. To make such solutions acceptable, all stakeholders must be involved in the requirements elicitation process. Due to the COVID-19 situation, alternative approaches to commonly used face-to-face methods must often be used. One aim of the current article is to share a unique experience from the Pharaon project where due to the COVID-19 outbreak alternative elicitation methods were used. In addition, an overview of common functional, quality, and emotional goals identified by six pilot sites is presented to complement the knowledge about the needs of older adults.Originally planned face-to-face co-creation seminars were impossible to carry out, and all pilot sites chose alternative requirements elicitation methods that were most suitable in their situation. The elicited requirements were presented in the form of goal models. In one summary goal model, we provide an overview of common functional, quality, and emotional goals.Different elicitation methods were combined based on the digital literacy of the target group and their access to digital tools. Methods applied without digital technologies were phone interviews, reviews of literature and previous projects, while by means of digital technologies online interviews, online questionnaires, and (semi-)virtual co-creation seminars were conducted. The combination of the methods allowed to involve all planned stakeholders. Virtual and semi-virtual co-creation seminars created collaborative environment comparable to face-to-face situations, while online participation helped to save the time of the participants. The most prevalent functional goals elicited were “Monitor health,” “Receive advice,” “Receive information.” “Easy to use/comfortable,” “personalized/tailored,” “automatic/smart” were identified as most prevalent quality goals. Most frequently occurring emotional goals were “involved,” “empowered,” and “informed.”There are alternative methods to face-to-face co-creation seminars, which effectively involve older adults and other stakeholders in the requirements elicitation process. Despite the used elicitation method, the requirements can be easily transformed into goal models to present the results in a uniform way. The common requirements across different pilots provided a strong foundation for representing detailed requirements and input for further software development processes. Demographic change—the aging of the population—is a fortunate consequence of the positive evolution of care and wellbeing, but also presents big challenges to developed countries. To reduce the financial burden on the health sector, it is necessary to focus on improving the quality of life of older adults through supporting their independence and overall health. Advanced information and communication technology (ICT) solutions have the potential to address these challenges and support “aging in place,” meaning that older adults can remain healthy in their familiar home environments and retain independence for longer periods. Aging in place can be supported by several monitoring devices and smart home solutions, which allow to monitor the health status of older adults and provide guidance in the home setting . Such soIncorporating ICT-based solutions that monitor the environment of an older adult and support her or his daily activities has several benefits. Besides the advantage of being able to stay at home, which is often more convenient for the older adult, the application of such solutions helps to reduce the burden of the healthcare and social care sectors . In addiTherefore, advanced ICT-based solutions aimed at supporting aging in place offer multiple solutions for different stakeholders, which help to improve the quality of life. It is widely accepted that the approach of sociotechnical systems, which comprise human, social, organizational, and technical factors, leads to systems that are more acceptable to end users and delivers better value to stakeholders . The firThere are a variety of methods that can be used for requirements elicitation . In seleAgainst the background described above, the aim of the current article is to share a unique experience from the Pharaon project where due to the COVID-19 outbreak alternative requirements elicitation methods and online tools were applied instead of face-to-face co-creation workshops. This situation provided us with a unique opportunity to seek answer to the following research question (RQ):RQ1. How can face-to-face co-design workshops be replaced with alternative methods for requirements elicitation?Previous literature has pointed out that there is a lack of knowledge about the needs and expectations of older adults and other stakeholders . In the RQ2. Which are the functional, quality, and emotional requirements common to different European countries aimed at supporting smart, healthy, and active living of older adults?In December 2019, 41 partners and six pilots from 12 European countries joined their efforts in the Pharaon project (EU Grant Agreement 857188) to make smart and active living environments for the aging population of Europe a reality by creating a set of integrated, highly customizable, and interoperable open platforms with advanced services, devices, and tools. A user-centric approach is used in the Pharaon project to maximize the final usability and acceptance of the open sociotechnical ecosystem being created by all stakeholders. The main end users of the Pharaon ecosystem will be older adults, whereas several other stakeholders, such as healthcare professionals, formal and informal caregivers, volunteers, governmental and non-governmental organizations, and others, have been identified and involved. The input gathered during the requirements elicitation process was utilized for representing user and pilot requirements for all six pilot sites from five countries involved in the project. The requirements served as a foundation to define the initial architecture of the Pharaon sociotechnical ecosystem and will guide the project activities to achieve and deploy a successful final system. The six pilot sites involved in the project are: Italy, Netherlands, Andalusia in Spain, Murcia in Spain, Portugal, and Slovenia.The most relevant challenges defined at the beginning of the project that will be addressed with the ecosystem are presented in The requirements elicitation process of the project followed roughly the co-design and requirements elicitation process prescribed by the The initial plan was to elicit requirements from stakeholders, particularly from older adults, in each pilot site through co-design workshops that would result in identifying functional, quality, and emotional goals proposed by the stakeholders. Several up-to-date methods of co-design for the elicitation of user requirements, such as DO-BE-FEEL™ , HOW-NOWDue to the COVID-19 outbreak and the lockdown in European countries, face-to-face co-creation seminars were impossible to carry out and contingency plans were developed for the involvement of stakeholders. Each pilot site chose alternative requirements elicitation methods that were deemed most suitable in their respective situations. These amendments were coordinated with local ethical committees in all pilot sites. The aim of the requirement elicitation remained the same—to provide an understanding of what activities by older adults and other stakeholders should be supported by the overall sociotechnical system to be designed, and what are the quality and emotional aspects of the activities to be supported.To answer RQ1 “How can face-to-face co-design workshops be replaced with alternative methods for requirements elicitation?,” we describe in section “Requirements Elicitation Methods Used” the alternative methods and accompanying digital tools that were used together with their strengths and weaknesses. Resulting from requirements elicitation, functional, quality, and emotional goals and the roles required for attaining these goals were identified. Each pilot site created goal models based on their input from elicitation. Despite the different challenges proposed at the beginning of the project by the pilot sites, several functional, quality, and emotional goals overlapped between the pilot sites. These goals answer RQ2 “Which are the functional, quality, and emotional requirements common to different European countries aimed at supporting smart, healthy and active living of older adults?.” The goals common to different European pilots and countries that were elicited are presented in section “Requirements Supporting Smart, Healthy and Active Living of Older Adults”.via online questionnaires. The stakeholders consisted of formal and informal caregivers, healthcare professionals, service and technology providers, and representatives of the public sector and universities.A total of 473 subjects (95 older adults and 378 other stakeholders) were involved in the requirements elicitation process. With 11 older adults, a face-to-face workshop was conducted before the outbreak of COVID-19, while the other 84 older adults were involved during COVID-19 restrictions remotely through other means. Similarly, 128 stakeholders were included in the requirements elicitation process through remote interviews and seminars. Additionally, 250 stakeholders were involved When choosing an alternative requirements elicitation method, pilots had to consider several different aspects, such as restrictions applied in their countries, the level of computer and Internet usage, and the need for approvals by ethical committees. As a result, the following two categories of methods can be distinguished that were used for identifying the needs and problems of older adults and other kinds of stakeholders: (1) methods without digital technologies and (2) methods with digital technologies. A face-to-face co-creation seminar was conducted by the Dutch pilot immediately before the outbreak of COVID-19 with older adults aged between 64 and 88 years. At the start of the workshops, the participants were asked to describe their typical day related to the four categories—food, movement, social contacts, outside activities—which were based on the aims of the Pharaon project. Participants wrote the elements of their day on differently colored post-its, indicating the four categories, and attached them to a poster. After discussing the posters with the group, they received another poster and were asked to recreate the first exercise, this time including what they would like to change or do differently in their daily life. In the last exercise, the participants were asked to write a short fantasy story describing how they could bridge the gap between the 2 days that were described.The main reason for conducting phone interviews instead of using video conference systems was the lack of accessibility and the level of computer skills of older adults. One limitation of phone interviews was that the pilot sites were unable to use illustrative materials, which had to be replaced with short stories. This underlined the need for storytelling skills by requirements engineers. Storytelling was particularly important because there was no social interaction between the participants that would have supported the co-creation of unique and common scenarios of applying various technologies. At the same time, the interviews were semi-structured, which made them flexible and dynamic, allowing to adapt the interview questions based on the knowledge of the person on the topic. A strength of using phone interviews was the possibility to acquire the views and problems of less digitally skilled older adults. Also, it cannot be underestimated that phone interviews provided older adults with opportunities for additional interactions during the period of social isolation.Due to the restricted access to older adults and overall social isolation, three out of six pilots focused their attention on identifying previously validated requirements from earlier projects and literature. A limhitation of this approach is that the end users and stakeholders are not directly involved at the initial requirements elicitation stage. However, as the results of applying this method indicated, distinguishing significant requirements identified by the previous research allows to form initial goal models, which can be validated and improved later together with the stakeholders. Indeed, as was the case with the pilot sites of Murcia in Spain and Portugal, this method was accompanied by other methods, where older adults and other kinds of stakeholders were directly involved at later stages. Therefore, the initial literature-based requirements elicitation provided the pilot site frameworks that improved the efficiency of the communication processes with the stakeholders.Online interviews were carried out by the Italian pilot with those stakeholders and older adults who were able to use video conferencing systems in compliance with the General Data Protection Regulation (GDPR) regulations. The advantage of online interviews over phone interviews was the possibility to use illustrative materials, such as videos or pictures, to introduce the topic and share video clips, which gave a more personalized touch to the communication. However, similarly to phone interviews, the component of co-creation with other participants was missing, which can be considered as a limitation of this approach.Using online questionnaires had several aims. For example, for Italian pilot online questionnaires served as a tool to evaluate the attitude toward technology by the seminar participants. This helped to focus and tailor the group discussion. Online questionnaires also facilitated interactivity during the seminars. In the Murcian pilot, an online questionnaire was used to obtain an overview of the needs, situation, and background of older adults and different stakeholders. In addition, online questionnaire helped to identify older adults, relatives, and healthcare professionals interested in participating in the forthcoming phases of the pilot, including virtual co-creation seminars. Therefore, online questionnaires should be considered as a supplementary rather than standalone tool for requirements elicitation.Only one pilot site conducted a virtual co-creation seminar with older adults, whereas four pilots out of six applied this kind of seminar with other kinds of stakeholders—caregivers and stakeholders dealing with technologies. The methods that were used for conducting virtual co-creation seminars were the DO-BE-FEEL™  method ado? (2) how should it be, i.e., what quality characteristics should it have? and (3) how should it make them feel? (4) who should do it, i.e., what roles should be involved? The corresponding keywords elicited from the participants were represented as a table consisting of the respective four columns. After the workshop, the keywords in the columns were arranged into a goal tree consisting of functional, quality, and emotional goals, and roles.In the workshops conducted by the DO-BE-FEEL™ method, after the introduction of the project and the aim, the participants were asked to think: (1) what should a solution that supports the active and healthy aging of older adults In the workshop conducted by the HOW-NOW-WOW method, three categories of ideas were identified from the discussions among the participants and grouped into three quadrants as follows: (1) NOW: Normal ideas, easy to implement; (2) HOW: Original ideas, impossible to implement; (3) WOW: Original ideas, easy to implement. Following, the best ideas were identified by voting by the participants, who were then divided into three groups to write down the scenarios for the best ideas belonging to the respective three categories.Across all the pilot sites, the virtual co-creation seminars created a collaborative environment and facilitated discussions among the participants. A disadvantage of this approach was that through digital tools, it was hard to capture the attention by the participants for a prolonged time. This deficiency could be mitigated to some extent by creating smaller discussion groups and including different interactive modalities, such as pop-up questions and brainstorming by means of digital solutions, which increased the involvement by the participants. At the same time, compared with face-to-face seminars, the seminar moderators noticed the reduction of social interaction among the participants. Additional shortcomings of virtual co-creation seminars were having no opportunity for small talk with the participants and not being able to get to know them better. However, it was pointed out that attending virtual seminars was logistically more convenient compared with face-to-face seminars as it helped to save time that would have been needed for travelling for some participants. This benefit was particularly emphasized by the stakeholders who are highly occupied, such as healthcare professionals.The Slovenian pilot conducted a semi-virtual co-creation seminar where the co-creation seminar with older adults was carried out by the caregivers of the residential unit housing older adults. The caregivers conducting the seminar were previously instructed by the project team and were provided with scripts for the seminar. The scripts consisted of guiding questions that helped to identify the needs of the older adults. The seminar was supported by the teleconference connection with the project team who were participating mainly as observers. The strength of such an approach was that the participants already knew their usual caregivers which made it easier for older adults to share their experiences and thoughts. However, the predefined scripts and the lack of previous experience in conducting such seminars by the caregivers reduced the flexibility and effectiveness of the seminar, as the caregivers conducting the seminar were not making any deviations from the provided scripts.The technology that was most frequently used for establishing an online connection with interviewees or seminar participants was Zoom, but Skype, Adobe Connect, and Microsoft Teams were also utilized. The selection of a tool significantly depended on the digital skills of the interviewees or participants but also on what was considered secure by the institution where the tool was used. The virtual workshops were accompanied by different solutions, which helped to increase the interactions with and between the participants, increase the involvement through short surveys, and support co-creation through enabling brainstorming and discussions in smaller groups. For group discussions in smaller groups, the breakout rooms’ feature of Zoom, Adobe Connect, or Microsoft Teams was used. The opportunity to create a breakout room within the meeting appeared to be very convenient for the participants as well as for the organizers because no additional web links for group discussions were needed. Moreover, when the group discussion was finished, the participants automatically returned to the initial meeting room. For documenting the ideas from brainstorming sessions and discussions in a manner that would be visible and editable for all participants, the pilot sites used Google Presentation, Google Docs or MURAL. The Italian pilot also used Google Forms for conducting short surveys during the seminars.The most important positive outcome of using alternative elicitation methods was the involvement of all planned stakeholders. In some cases, using methods without digital technologies were used, such as phone interviews, enabled to include older adults with lower levels of digital literacy, who may not have been included under different circumstances. In addition, incorporating requirements from similar projects and literature further broadened the knowledge about the needs of the target group and helped to form a more exhaustive list of requirements which were validated with the stakeholders at later stages of the process. The application of the digital tools enabled several knowledgeable and experienced healthcare professionals to attend the virtual seminars and participate in the requirements elicitation process as virtual participation is less time-consuming compared with attending physical seminars. Another positive outcome was that even in a virtual setting, it was possible to create a collaborative and inclusive environment and fulfil the purpose of co-creation seminars.Despite several benefits of applying digital tools for requirements elicitation, which offered an opportunity to involve in the elicitation process older adults and stakeholders without direct contact, several difficulties also had to be overcome. The barriers most frequently reported by the pilot sites were technical problems, such as the overall connectivity, and audio and video problems which were reported by 75% of the pilot sites who applied digital technologies for requirements elicitation. Another frequent challenge faced by the pilot sites was the overall digital literacy of older adults and their lack of understanding of technical terms or functionalities. This occasionally created confusion and often caused misunderstanding of a question, which resulted in rephrasing the question using a simpler language. Therefore, some bias can be present in the answers by the older adults. For the same reasons stated above, the moderators of the virtual seminar conducted with older adults were not able to apply usual techniques for warm-up and holding the attention that they typically use in face-to-face seminars, and alternatives had to be identified.The requirements were elicited by the pilots of the Pharaon project using different methods overviewed in section “Requirements Elicitation Methods Used” and were then presented as agreed in the project in uniform way in the form of goal models . DespiteThe most prevalent functional goals were “Monitor health,” “Receive advice,” and “Receive information about activities/courses/initiatives” which were identified by 83% of the pilots which are sub-goals for “Support health” and “Participate in social activities” . The mosThe most remarkable idiosyncratic functional goals elicited by the pilot sites were on the one hand the goals related to the natural environment by the Portuguese pilot, such as “raise awareness of green and blue areas” and “report needed environmental measures” and on the other hand the overly health-related goals identified by the Murcian pilot site, which are concerned with treatments, therapy schemes, and follow-up measures.At the beginning of the project, all pilot sites identified the challenges of the Pharaon project applying to them . As a reThe results of this paper extend the current research literature in two ways. First, they provide a detailed information about different requirements elicitation methods and their combinations that could be applied during COVID-19 or similar restrictions where direct contact with stakeholders is impossible. The results determine on an unprecedented scale how face-to-face co-design methods can be replaced with alternative methods for requirements elicitation and what is the possible effect of applying a variety of alternative methods on the outcomes of the elicitation process (RQ1). Second, the analysis of the requirements elicited from six pilot sites originating from five European countries extends our knowledge and the current literature on functional, quality, and emotional requirements for ICT-based systems that support smart, healthy, and active living of older adults in Europe (RQ2). Following, in sections “Requirements Elicitation From Older Adults” to “Requirements Elicitation—Virtual Co-creation Seminars” we discuss in more detail some aspects of answering the research question RQ1. Finally, in section “Requirements for Supporting Smart, Healthy, and Active Living of Older Adults” we elaborate on answering the research question RQ2.Requirements elicitation has a major impact on the effectiveness and usability of ICT-based solutions that should satisfy the needs of end users . TherefoAnother challenge to the requirements elicitation was the overall knowledge of technical terms by older adults which made it difficult to discuss some aspects of the requirements especially when no virtual tool was available for providing visual explanations. This resulted in simplifications in the explanations, which may have caused some biases. Our experience with requirements elicitation from older adults also highlights the importance of reserving time for storytelling as the stories shared by older adults involve the needs and problems faced by them, which can be turned into requirements for the ICT-based system.Phone and virtual interviews allowed for the involvement of the older adults in the elicitation process, although some limitations compared with face-to-face seminars were present. These limitations are in line with the previous research where the impossibility of using body language and technical issues has been reported . HoweverIn the Pharaon project, only the Murcian pilot site managed to conduct a completely virtual workshop with older adults . TherefoAnother alternative method that was used for requirements elicitation in the Pharaon project, which seems to be underused in the requirements elicitation, is the review of literature and similar previous projects to identify possible functional, quality, and emotional requirements. Literature review is very common in research communities when, for example, an intervention is being planned  or a resAt the same time, considering previous experience helps to avoid possible negative consequences on the end users . For exaIn the Pharaon project, virtual co-creation seminars were mainly used for eliciting requirements from other kinds of stakeholders, such as formal and informal caregivers, healthcare professionals, and service providers. Based on the experience gained from the Pharaon pilot sites, such virtual co-creation seminars constitute a viable alternative to face-to-face seminars because the participants were actively involved and contributing. However, additional effort had to be exerted on incorporating a variety of virtual tools that foster the involvement and keep the participants focused on the topic. In our case, virtual tools that enable pop-up questions or enable simultaneous mind mapping and document editing features proved to be efficient for facilitating the involvement. In addition, our experience confirmed that group discussions should be carried out in smaller groups so that everyone would have an opportunity to express their opinion. A significant advantage of the virtual co-creation seminar highlighted by the participants was the time-saving aspect as there was no need to travel, and therefore, a larger number of healthcare professionals were able to join.Overall, our experience gained in the Pharaon project indicated that combining different requirements elicitation methods, with or without using digital solutions, allowed for effective involvement of stakeholders despite their age or profession. Moreover, the inclusion of the literature reviews and results from previous projects extends the knowledge obtained from co-creation seminars and this way increases the evidence-based features of the resulting ICT-based solution.Previously, the lack of knowledge about the needs and expectations of older adults and other stakeholders has been pointed out . AgainstInformation and communication technology-based solutions for health management keep track of different health indicators, support healthy and active aging, provide suggestions, and track activities . A promiSupporting social interaction seems to be obligatory for ICT-based home care systems aimed at older adults as they can have a significant effect on the physical and mental health of older adults . In factQuality goals that were most frequently reported by pilot sites were concerned with user experience—“simple to use” and “accessible.” Quality goals and emotional goals common to the pilot sites are also represented in For the quality goals, the requirements elicitation performed in the Pharaon project indicated that the stakeholders value tailored, personalized, and smart solutions. Personalization is an important quality goal as it improves the user adherence  and helpThe two most frequently reported emotional goals by all of the pilot sites were “involved” and “empowered.” Therefore, as is already pointed out in section “Functional Goals”, supporting social interactions seems to be an indispensable feature that helps to retain the quality of life of an older adult in a home setting. Other emotional goals proposed by several stakeholders were “sense of belonging,” “being involved,” and “reassured.” These emotional requirements indicate the need for smart solutions, which can take into account the particular needs of each end user and adequately react to the information gathered by the monitoring systems.The identified goals sound generic, but they constituted an important starting point for identifying scenarios for achieving the goals  and detaWe acknowledge that the main weakness of the current study is the paucity of requirements validation. As of now, the functional, quality, and emotional goals have been identified and presented in the form of goal models. The scenarios for achieving the goals  have beeThis study focused on identification of the needs as the first part of the iterative user-centered co-design process conducted in the Pharaon project. The co-design process is presented in The extreme situation associated with the COVID-19 outbreak and lockdowns provided the project partners with an invaluable experience of requirements elicitation using alternative methods and incorporating online tools. We hope that our article inspires and supports the involvement of end users in the requirements elicitation process to provide solutions that meet the needs of end users even under such challenging circumstances. We encourage other researchers to share their experience with requirements elicitation by means of digital solutions during the COVID-19 restrictions to provide guidance to the research community.Our experience with requirements elicitation under the circumstances created by the spread of COVID-19 confirmed that there are acceptable alternative methods to face-to-face co-creation seminars that effectively involve older adults and other stakeholders in the elicitation process. As for the alternative methods without virtual components, the lack of co-creation elements must be acknowledged. At the same time, some methods, such as the review of previous literature and projects, have a potential to strengthen the requirements elicitation process through creating a broader context for the ICT-based solution to be designed and involving evidence-based components. As for the alternative methods with a virtual component, even if human contact is essential, virtual co-creation seminars can be considered as an acceptable method for active involvement of stakeholders in the co-design process. We showed that despite the requirements elicitation method used, the results can be effectively presented in the form of a goal model that facilitates the communication between technical and non-technical stakeholders. Even more importantly, we identified common functional, quality, and emotional requirements for supporting smart, healthy, and active living of older adults in five European countries and summarized this research result by the overall goal model of the Pharaon project.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. Written informed consent for participation was not required for this study in accordance with the national legislation and the institutional requirements.KM wrote the first draft of the manuscript. The design of requirements elicitation was led by KT with in close collaboration with other authors. All authors contributed to the collection of data, manuscript revision, read, and approved the submitted version.via the IT Academy programme. This article is based upon work from COST Action CA16226 SHELD-ON—Indoor living space improvement: Smart Habitat for the Elderly, supported by COST (European Cooperation in Science and Technology). COST (European Cooperation in Science and Technology) is a funding agency for research and innovation networks. Our Actions help connect research initiatives across Europe and enable scientists to grow their ideas by sharing them with their peers. This boosts their research, career and innovation. More information in www.cost.eu.The research work reported in this article has received funding from the Pilots for Healthy and Active Ageing (Pharaon) project of the European Union’s Horizon 2020 research and innovation programme under the grant agreement no. 857188 and from the European Social Fund 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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


The upcoming agricultural revolution, known as Agriculture 4.0, integrates cutting-edge Information and Communication Technologies in existing operations. Various cyber threats related to the aforementioned integration have attracted increasing interest from security researchers. Network traffic analysis and classification based on Machine Learning (ML) methodologies can play a vital role in tackling such threats. Towards this direction, this research work presents and evaluates different ML classifiers for network traffic classification, i.e., K-Nearest Neighbors (KNN), Support Vector Classification (SVC), Decision Tree (DT), Random Forest (RF) and Stochastic Gradient Descent (SGD), as well as a hard voting and a soft voting ensemble model of these classifiers. In the context of this research work, three variations of the NSL-KDD dataset were utilized, i.e., initial dataset, undersampled dataset and oversampled dataset. The performance of the individual ML algorithms was evaluated in all three dataset variations and was compared to the performance of the voting ensemble methods. In most cases, both the hard and the soft voting models were found to perform better in terms of accuracy compared to the individual models. Agriculture evolves at a rapid pace nowadays, transitioning into a new era known as Agriculture 4.0. Considering the challenges of modern agriculture , Agriculture 4.0 aims to engage new technologies and methods in order to alleviate the existing challenges, reduce the risks and lead to more efficient and safer production. To this end, it engages a plethora of advanced Information and Communication Technologies (ICTs) .In addition to this evolution, there is an upward trend in food needs that, as reported by the United Nations’ Food and Agriculture organization, will reach a 70% increase in 2050 as compared to the current production, so as to cover the needs of the growing population, which is expected to be around 10 billion in 2050 . ConsideIn Agriculture 4.0, Wireless Sensor Networks (WSNs) and Internet of Things (IoT) solutions are extensively used, providing numerous benefits to the farmers  . HoweverIn agriculture, safety is a major concern, and any kind of disturbance or distortion may pose important challenges and lead to dangerous consequences ,11. NetwThe use of ensemble methods provides an overall better performance in many instances of problems, as compared to the performance of individual classifiers . Based oThe remainder of this paper is structured as follows: Network traffic analysisNetwork threatsNetwork traffic monitoringNetwork securityNetwork intrusion detectionNetwork traffic classificationOver the last two decades, both academics and researchers have shown an ever-increasing interest in network traffic monitoring, as depicted in The results were filtered to depict the number of publications between 2000 and 2020 .Aiming at improving security in IoT applications, several ML-based network traffic classification solutions have been proposed. Liu et al.  presenteUllah and Mahmoud  presenteThe aforementioned studies mainly refer to IoT network monitoring, as well as to solutions for detecting anomalies, abnormal/malicious behavior and intrusions. Due to the fact that IoT solutions are widely adopted in Agriculture 4.0 , those sIn ML, ensemble classifiers are created by several single estimators (base estimators) that cooperate with each other based on certain training and classification methodologies . VariousSeveral solutions from the e-Commerce domain can also be utilized in the agriculture sector . For exaA part of the current research work has also been implemented in the context of the ENSURESEC project as a subcomponent of a communications monitoring toolset in an e-Commerce environment. The ENSURESEC project has received funding from the European Union’s Horizon 2020 research and innovation program. It aims to protect the whole range of modern e-Commerce by addressing a wide variety of threats. More specifically, it focuses on a wide variety of products ranging from virtual products and services purchased online to physical products bought online and delivered to the customers and aims at addressing numerous threats ranging from e-Commerce web applications attacks to frauds committed by customers or insiders, delivery issues, etc. .The aforementioned toolset offers advanced monitoring capabilities aiming to ensure that the communication protocols in use, as well as the underlying communication infrastructure, function properly and safely. In this direction, certifiably correct verification methodologies  are adopted, and various functionalities are included in the toolset. One of these functionalities is called Threat and Incident Detection and utilizes parts of the methodology described in Advanced threats detection mechanisms are of vital importance for well-designed and secured e-Commerce systems in order to protect and ensure sensitive data that is being targeted by malicious users. Within this scope, the current study evaluates the performance of distinct ML algorithms in A Threat Objects Fusion functionality through which users can fuse different objects into a unified objectA Similarity Degree Calculation feature that enables users to execute a character-by-character complex comparison algorithm among all the types of objects stored in or retrieved from a specific Knowledge Base, after the execution of certain processesAn Association Rule Engine that can be used for revealing hidden patterns and relations while exploring a populated databaseA Visualization functionality that can be used for the interactive representation of populated ontologies in the form of graphsAn Advanced Reasoner through which users can apply rule-based logical reasoning into the existing Knowledge BaseFive more functionalities were included in the so-called “Communication Monitor” toolset namely:Further analysis of these functionalities is beyond the scope of the current research work.The Threat and Incident Detection functionality, together with the other functionalities of the Communication Monitor, are depicted in Τhis section is divided into two sub-sections; the first sub-section describes the dataset used for the evaluation of the proposed solution, whilst the second focuses on the description of the proposed methodology, i.e., the algorithms and methods engaged to produce the desired results.For the evaluation needs of this study, the NSL-KDD dataset  was usedThis very task is directly associated with the aim of the methodology analyzed in the context of this paper, which is to detect and classify threats in network traffic. Moreover, the KDD Cup 1999 dataset contains a standard set of data to be audited, which encompasses a wide variety of intrusions. An optimized set of this data, widely used by security professionals, is also contained in the NSL-KDD dataset. There are several distinct types of cyber-attacks; 22 of which are contained in the NSL-KDD training dataset, as presented in The top ten types of attacks considering the number of records contained in the NSL-KDD training dataset are depicted in As previously mentioned, the training dataset contains 22 types of attack traffic, whilst the test dataset contains 37 types . The exi‘benign’ for benign behavior‘dos’ for DoS attempts in an online system‘probe’ for brute-force attack probing by malicious actors‘r2l’ for unauthorized attempts of accessing from remote machines‘u2r’ for Privilege escalation attacks in the target machineThe dataset contains different attack types, as described in All the instances of the NSL-KDD dataset grouped into five different categories are depicted in There are no duplicated/redundant instances, and thus, the classifiers will not be biased by these recordsEvery difficulty level group contains a number of instances that is inversely proportional to the percentage of instances in the KDD Cup 1999 dataset. This leads to a wide range of classification rates of the distinct ML methods. Thus, the evaluation of different ML algorithms can be more accurateThe size of both the train and the test set is configured in order to offer the ability to whoever is interested in running their experiments on commercially available PCs. Therefore, the direct comparison of different research efforts that used the NSL-KDD dataset is feasibleThe NSL-KDD dataset optimizations as compared to the original KDD dataset are as follows :There arRandom undersampling of the majority class of the used datasetDirected undersampling of the informed class of the used datasetOversampling with replacement of the minority class of the used dataset to generate a more balanced datasetDirected oversampling, where specific dataset information is created and replaced in a non-random mannerAdjusting the costs of the various dataset’s classesAdjusting the decision thresholdAdjusting the estimation of the probabilistic factor at the tree leaf, mostly in cases where decision trees algorithms are involvedOne important issue detected in the NSL-KDD dataset that can affect the performance of the suggested classifiers is the unbalanced data, commonly known as a class-imbalance problem. As Chawla et al.  stated, To avoid negative side effects stemming from the use of distinct methods, different types of resampling methods can be combined. For the purposes of the current study, the “random undersampling” and the “oversampling with replacement of the minority class” data resampling techniques are adopted. These techniques are applied individually in each distinct algorithm in order to highlight the differences between the datasets that have undergone resampling and the initial, raw imbalanced dataset. In recent years, ensemble learning models are becoming increasingly popular among researchers  in the fBoosting BaggingStacking or stacked generalizationBlendingTwo popular voting ensemble methods are (i) hard voting, which is suitable for models that predict distinct class labels in cases where the outputs of classifiers are not independent, as well as for binary class problems when the number of included classifiers is not odd, and (ii) soft voting, which is mostly used in cases where the developed models predict probabilities for each contained class, as well as when it is clear that a classifier returns better output results in comparison to the other classifiers included . More spThe methodology proposed in this study aims to evaluate hard voting and soft voting ensemble methods. These two methods encompass five different ML algorithms namely; KNN, linear SVC, DT, RF and SGD, as shown in KNN is one of the most studied supervised ML classifiers. KNN uses distance metrics  in order to classify each data instance to its nearest neighborhood ,49. For The algorithms were developed in Python version 3.8, and the sci-kit learn framework ,57 was uEach of the algorithms introduced in TP stands for True Positives, i.e., the attack predictions that are actually attacksTN stands for True Negatives, i.e., the non-attack predictions that are actually non-attacksFP stands for False Positives, i.e., the attack predictions that are not actually attacksFN stands for False Negatives, i.e., the non-attack predictions that are actually attacksThe calculated accuracy results for the three different variations of the dataset  for every method used  are presented in The overall accuracy results are presented in Based on the results presented in the above figures, as well as in It is worth mentioning that the model with the highest accuracy, among all the algorithms and datasets  combinations, was the soft voting ensemble model using an undersampled dataset, while the SGDC algorithm, using the initial dataset had the lowest accuracy.Another interesting remark based on the aforementioned results is the increased accuracy that was noticed by adopting the selected dataset resampling methods. Except for the DT algorithm, where the normal sampling was found to achieve higher accuracy compared to the two resampling methods, in the rest of the six algorithm implementations, datasets that had undergone resampling achieved better classification performance.The goal of this study was to present a comparative analysis of the performance of five different ML classifiers when they are applied individually, as well as when they are part of hard and soft voting ensemble methods. For the evaluation of these methods, the NSL-KDD dataset was utilized in three variations . Hard voting and soft voting ensemble models were found to achieve a better overall accuracy than the individual classifiers in most cases.The analyzed solutions can be used for network traffic classification in the context of Agriculture 4.0. To this end, this paper includes a related works section where several studies about network traffic monitoring and classification were presented. These studies refer to contemporary solutions that are directly connected with the agriculture domain or the ICT technologies that are engaged in it. In the agriculture sector, cyber-security is of utmost importance, so the engagement of new tools and technologies, including ensembles of ML methods, can contribute to a safer and more robust network infrastructure encompassing a plethora of devices.Details were also provided about how the analyzed methodology was implemented in the context of a communications monitoring toolset in an e-Commerce related EU-funded project.The use of ensemble ML models is an expanding research topic, and new possibilities are explored in order to enhance the capabilities and the performance of single ML classifiers in this domain. The results presented in this study seem to be very promising concerning the utilization of ensemble methods in network traffic classification. A future step of this analysis would be to integrate it in an application where historical and near real-time analyses for network attacks classification are required so as to detect threats and abnormal traffic in order to isolate such traffic and/or provide alerts. Furthermore, we propose that the evaluation of the performance and efficiency of such models is also performed in other datasets and domains. We also suggest the examination of different ensemble models other than hard and soft voting. Another useful approach would be to engage different ML classifiers and combine various solutions in order to investigate the best option. Furthermore, the engagement of such methods may be expanded in different domains other than agriculture and e-Commerce in order to discover new possibilities and restrictions imposed by different kinds of datasets.


Preventive chemotherapy interventions have been identified as key tools for malaria prevention and control. Although a large number of publications have reported on the efficacy and safety profile of these interventions, little literature exists on end-user experience. The objective of this study was to provide insights on the perceptions and attitudes towards seasonal malaria chemoprevention (SMC) and intermittent preventive treatment of infants (IPTi) to identify drivers of and barriers to acceptance. A total of 179 in-depth qualitative interviews were conducted with community health workers (CHWs), health center managers, parents of children receiving chemoprevention, and national decision makers across eight countries in sub-Saharan Africa. The transcribed verbatim responses were coded and analyzed using a thematic approach. Findings indicate that, although SMC is largely accepted by end users, coverage remained below 100%. The main causes mentioned were children’s absenteeism, children being sick, parents’ reluctance, and lack of staff. Regarding IPTi, results from participants based in Sierra Leone showed that the intervention was generally accepted and perceived as efficacious. The main challenges were access to water, crushing the tablets, and high staff turnover. SMC and IPTi are perceived as valuable interventions. Our study identified the key elements that need to be considered to facilitate the expansion of these two interventions to different geographies or age groups. Since 2000, tremendous gains have been made in reducing the burden of malaria thanks to global control efforts. However, since 2016, this progress has plateaued, and malaria remains one of the most devastating infectious diseases, with an estimated 229 million infections and 409,000 deaths in 2019, mainly children under the age of five in sub-Saharan Africa . This arP. falciparum is sensitive to both of these medicines. SMC was first recommended by the WHO in 2012, followed by the development of regional and national plans for its implementation [Seasonal malaria chemoprevention is defined as the intermittent administration of full treatment courses of an antimalarial medicine to children aged three to 59 months in areas of highly seasonal transmission during the rainy season. SMC consists of the monthly administration of a full course of SPAQ treatment. The duration of treatment usually lasts four months. The objective is to prevent malarial illness by maintaining therapeutic antimalarial drug concentrations in the blood throughout the period of greatest malarial risk. The WHO recommends SMC with a combination of two antimalarial medicines, sulfadoxine-pyrimethamine + amodiaquine (SPAQ), in areas with highly seasonal malaria transmission in the Sahel sub-region of Africa, where entation . During entation . In Seneentation . AccordiP. falciparum parasite, since Pfdhps 540 mutation is associated with SP resistance [Intermittent preventive treatment of infants (IPTi) is a course of antimalarial medicine delivered to infants using routine immunization services. Importantly, IPTi should not be deployed concomitantly with SMC . IPTi trsistance . Adminissistance . It has sistance ,11. A resistance . They coOther preventive interventions have been trialed or piloted, including intermittent preventive treatment in school children (IPTsc), mass drug administration (MDA), and post-discharge malaria chemoprevention ,14. PostBecause the adoption and implementation of SMC has been fragmented and IPTi limited to Sierra Leone, we designed a survey to better understand how SMC and IPTi interventions are perceived in a selection of countries. In addition, as IPTi is delivered via the Expanded Programme on Immunization, we investigated the hurdles facing this program that could impact the potential implementation of IPTi. Lastly, as clinical trials are currently investigating the impact of providing intermittent administration of full courses of treatment of antimalarials to children recovering from severe anemia, we sought to better understand the management of children under five years of age hospitalized for severe anemia.To understand in-country approaches to malaria chemoprevention in children, eight countries in Africa were selected based on their past and current experiences with various malaria chemoprevention strategies, as well as some countries that did not implement any intervention. These countries were also selected because of their geographic diversity within Africa and their varying population size. The first arm of this survey consisted of interviews with people selected for their first-hand knowledge about chemoprevention, as well as their role in decision-making processes at the national level. These people are referred to as key informants. Research participants were selected based on their involvement in malaria management, and included National Malaria Control Programme (NMCP) coordinators or staff members, key opinion leaders (KOLs), such as clinicians or professors, and in-country malaria organization representatives. Sampling was done through a mix of purposive and snowball method. Participation in the survey was voluntary, and no incentive or compensation was offered to participants. Five discussion guides were produced by Medicines for Malaria Venture and are provided in a https://www.sanisphere.com, accessed on 10 May 2021). The discussion guides are available as Seven discussion guides were generated by Medicines for Malaria Venture and shared with its field partner, Sanisphere . To judge coding reliability, Cohen’s kappa was used to examine the consistency between both coders. Findings of this analysis indicated that the coefficients for each variable examined were 0.72 for health center managers, 0.61 for community health workers, and 0.73 for parents, with an aggregated score of 0.69. Given that attaining a kappa value of 0.6 or higher is considered a substantial level of mutual agreement, we determined that our coding was reliable . Cohen’sFor key informants, personalized introduction emails were sent by the authors to 32 potential key informant participants, outlining the scope of the project. Seven (21%) contacts declined to participate in the survey because they were not involved in malaria chemoprevention, but provided references and introductions to other key informants. Eleven (32%) contacts did not respond or were not able to participate in the timeframe allocated for that research. No one from Tanzania was interviewed, as it was not possible to schedule a time for the interviews during the period allocated to the study. A total of 14 contacts accepted the invitation and were interviewed, including six NMCP coordinators, two NMCP staff members, four professors from academic or research centers, and two local UNICEF representatives. The interviews took place from 19 June to 25 July 2019. One respondent in the Democratic Republic of Congo (DRC) provided feedback by email. Interviews lasted from 15 to 60 minutes, with an average of 33 min.The final sample for the field survey consisted of 94 health center managers, 46 community health workers, and 25 parents, who were all interviewed in the health center they worked for or were associated with. The total number of respondents per type and per country is shown in The number of participants per country is shown in The understanding of current SMC practices was investigated by interviewing a total of nine NMCP representatives, KOLs, and in-country partners from Cameroon, Ghana, Senegal, and Nigeria. According to the nine key informants, the SMC intervention implementation was facilitated by the fact that good results were obtained during trials and local pilots. Engagement of policy makers and community leaders was mentioned as the key driver of implementation and acceptance of the intervention. The hurdles encountered were mainly linked to adherence to the program and administration of the second and third doses of SPAQ, as well as limited funding in Nigeria. In Senegal, the extension of SMC to children five to 10 years of age was triggered by the early SMC trials, which demonstrated that children in this older age group were just as affected by malaria as the younger children. According to the key informants from other SMC-implementing countries interviewed for this survey, a similar extension to five to 10 years old did not occur mainly because of limited funding and the absence of a pilot study in their countries to demonstrate the same benefit in the older age category.Results from the interviews with 37 health center managers, 46 community health workers, and 20 parents in Cameroon, Ghana, Nigeria, and Senegal are presented below.Positive perception of SMCSMC was generally positively perceived by the survey participants thanks to its efficacy in preventing malaria .Samples of illustrative quotes are provided below.Efficiency: “The drug is very effective. The reason I said this is because before the start of this chemoprevention, during raining season, facilities are usually congested with sick people. All of the beds for admission would have been occupied. But due to the effectiveness of the chemoprevention such congestion is now a thing of the past.” Health center manager, NigeriaCost: “SMC reduces expenses for us parents. There are too many mosquitoes here; without prevention it would be too expensive to treat children. Malaria access requires spending in health centers, yet prevention is free.” Mother of two children, Cameroon.Barriers to SMC implementationThe main barriers to SMC implementation mentioned by healthcare professionals were the side effects, driven by respondents from Senegal, a number of staffing issues, including lack of staff, transportation to households, and absence or delay in payment of incentives to staff, and poor acceptance from parents .Adverse effect: “During the first day we had less problems, but on the second day, third day we had all the problems in the world because it was at that moment that the side effects started and we had many cases of refusal because the parents could not bear these effects in the children and they said that the drugs are not good. In the second passage, it was even worse, we had many cases of refusal; when we went to discuss with the parents, they said downright ‘no, all the children were sick’, we tried to talk to them but there was nothing to do.” Health center manager, Senegal.Areas for SMC improvementThe three main ways to improve SMC delivery according to healthcare professionals who participated in the survey are: (1) better education of parents to increase their acceptance of SMC ; (2) on time payment of incentives (Cameroon), offering a better incentive plan to cover the transportation fee, or offering a small incentive to parents (Nigeria and Ghana); and (3) improvement of the side effects associated with the treatment . For parents involved in the survey, the main suggested improvements were extension of SMC (to older children and even adults and to regions that are not currently covered) and extended duration (coverage for a longer period than the current four months) . Several potential barriers to SMC were specifically investigated during the survey. These included issues around drug stocks, staffing and workload, inadequate coverage, and potential conflicts with other public health campaigns.Availability of the drug: health center managers and community health workers who participated in this study anecdotally reported SPAQ out of stock situations. Most of these situations were corrected within 24 hours and had no impact on children’s malaria protection.Staffing and workload: Health center managers with the lowest number of community health workers were those most in need of an increase in staff, requesting on average 36% more community health workers. Half of the community health workers who had participated in the survey said the workload associated with SMC was fine, while the other half thought it was too much. In terms of turnover, most parents who participated in the survey in Nigeria and Cameroon mentioned that community health workers varied frequently, while parents from Senegal and Ghana reported that it was steadier.Coverage: According to health center managers and community health workers who participated in the survey, 88% and 92% of eligible children received the first dose of SMC each month, respectively. In terms of the second and third doses, an estimated 11% of children did not receive it, according to one health center manager. This number increased to 22% of children, according to community health workers. Respondents from Cameroon, Ghana, and Nigeria indicated that the main reasons for not providing SMC to children was absence or illness, while in Senegal it was parental refusal. A number of measures have been put in place by respondents to ensure that children in Cameroon, Ghana, and Nigeria receive the second and third doses of SMC, including providing advice to mothers, collecting empty blisters as proof of administration, and the use of recording cards to keep track of administration.Coverage: “… without lying to you, officially almost all the children received. But unofficially, those who have actually received are few, given the demotivation of community health workers on the field. Hence, it can be estimated that 25% of children have not received their SPAQ dose.” Health center manager, Cameroon.Conflicting campaigns: Lastly, although conflicting interventions were mentioned as a potential barrier, it was noted that SMC campaigns tend to run in isolation, according to most health center managers and community health workers interviewed. On the rare occasions when other interventions took place at the same time as SMC, these caused no conflict. Some anecdotal comments pointed to possible benefits of running net distribution, nutrition education programs, or vaccination campaigns at the same time as SMC.IPTi was investigated by interviewing two key informant respondents from Sierra Leone, the only country where IPTi is currently routinely performed. In addition, experience with IPTi was investigated in the three countries that piloted IPTi, namely the DRC, Ghana, and Senegal, by interviewing two key informants per country. Finally, the general perception of IPTi was obtained from three key informant respondents from Cameroon and Uganda. In Sierra Leone, the main drivers for implementing IPTi were the very high mortality rate in infants and the absence of seasonal transmission that made SMC unsuitable. IPTi adoption was facilitated by the good perception of SP, thanks to the malaria prevention in pregnancy program and the important role played by community health workers in sensitizing the community to the intervention. The main hurdles were related largely to logistic issues, such as availability of clean water, drug shortages, nurse turnover, and poor attendance to Expanded Programme on Immunization visits.The DRC, Ghana, and Senegal piloted IPTi, but decided not to implement it for the following reasons: lack of involvement of policy makers from the start of the process, logistics issues around synchronization with other programs, the belief of some healthcare professionals that infants are protected by their mothers’ antibodies at the beginning of life, unconvincing results at the end of the trial, fear of SP side effects, overexposure to SP in infants due to their mother receiving SP during pregnancy, absence of solutions past the age of one, and the gap between two vaccination programs, leading to a gap in coverage. Cameroon and Uganda did not pilot IPTi and do not plan to implement it, because they are concerned about resistance to SP. They foresee difficulties in integrating it into the Expanded Programme on Immunization, the acceptance of parents is expected to be low, and the gap between two administrations does not provide full coverage. Nigeria is the only country that envisages implementing IPTi to reduce malaria burden in infants.In addition to key informant interviews, IPTi was investigated by interviewing 15 health center managers and five parents in Sierra Leone. According to the former, the advantages of IPTi were its effectiveness in reducing the number of malaria cases, the absence of side effects, and the good supply of SP. The main barriers were the difficulties in preparing the drug, with crushing the tablets being the hardest and most time-consuming step of the treatment; the limited access to commodities, such as clean water and cups; and the lack of training of staff/nurses due to high turnover rates. Participating parents were largely satisfied with IPTi, because they perceived it as efficacious in protecting infants from malaria and having no side effects. The main areas for improvements highlighted were an increase in drug stocks to avoid having to return to the facility, access to clean water, and availability of a pediatric formulation.Perception, drivers, and barriers of the Expanded Programme on Immunization were investigated by interviewing 91 health center managers involved in the Expanded Programme on Immunization in all eight countries: Cameroon, the DRC, Ghana, Nigeria, Senegal, Sierra Leone, Tanzania, and Uganda. The Expanded Programme on Immunization was largely well-perceived by communities and parents, according to the health center managers who participated in the survey. The stated main hurdles fell into five broad categories: logistics-related issues, such as running out of stock or inadequate storage of product; lack of knowledge or understanding of the program by parents and lack of endorsement by community leaders; children not showing up; staffing issues, such as a lack of staff and high staff turnover; and transportation difficulties both for parents to come to the Expanded Programme on Immunization center and for staff to travel to communities . Reported attendance for vaccination visits ranged from 66% to 93% of eligible children at 10 weeks, 68% to 90% of eligible children at 14 weeks, and 54% to 88% at nine months. The measures put in place to increase attendance to Expanded Programme on Immunization visits by survey participants included having a system that tracks the no-shows, raising awareness amongst parents, developing outreach services, and providing an incentive to parents.Post-discharge malaria chemoprevention is currently being investigated in several clinical trials in Uganda, Kenya, and Malawi. We evaluated the degree of knowledge and interest in this intervention amongst the 14 NMCPs, KOLs, and in-country malaria organizations included in our survey. Very little knowledge about this intervention was observed among all 14 participants, even in Uganda, where it has been evaluated in a clinical trial.In addition, our evaluation shows that the 94 health center managers who participated in the research were largely unfamiliar with PMC. Therefore, the focus was on capturing some basic information about the management of patients under five years of age presenting with severe anemia who required hospitalization. Forty-three percent of the health center managers we interviewed said they either do not see or do not manage these patients. The remaining 57% who do take care of these patients claimed that they performed malaria tests in 94% of children, with 66% coming back positive. Transfusion was needed for 77% of children, with 86% of them receiving it as reported by our sample. The biggest issues faced by interviewed health center managers regarding the treatment of children under five years of age with severe anemia were parents’ financial difficulties, lack of blood for transfusion, artesunate out of stock, delay in seeking treatment, and poor adherence with the treatment.The efficacy and safety of malaria chemoprevention interventions in children and infants have largely been documented, and numerous publications of clinical trials results are available. There is, however, little literature on end users’ experiences outside of clinical trials. This qualitative study provides novel and valuable insights on the perceptions and attitudes towards SMC and IPTi from those who implement it in the field—health center managers, community health workers, and parents—as well as national representatives who are involved in setting up malaria elimination policy in their country.Regarding SMC, the results from this study indicate that it is largely well-perceived by end users. The good efficacy and generally favorable safety profile, as well as the growing experience with this intervention, drove the positive perception. Similar findings have been reported by other researchers, including a recent publication of a qualitative study among parents and community health workers in the upper west region of Ghana, which demonstrated that the high acceptability of the SMC intervention was driven by the perception that SMC had helped reduce the prevalence of malaria . The sucDespite SMC’s high acceptability at the central and field levels, coverage remained below 100%, meaning that not all eligible children received chemoprotection, and not all who received it completed the full seasonal course. In our survey, health center managers and community health workers reported that 90% of eligible children received the first dose each month at best. The consequences of poor adherence to the SMC program can be dramatic, as it raises the risk of resistance to the drugs used and impairs the efficacy of the intervention . AlthougThe potential hurdles to SMC implementation are not limited to uptake or adherence issues. In their 2017 publication, Coldiron et al. identified logistical burdens, the use of preventive medication requiring a three-day course of therapy, and geographical difficulties as potential challenges to full SMC implementation . Our surRegarding IPTi, results from participants based in Sierra Leone indicate that the intervention is largely accepted and integrated in the Expanded Programme on Immunization. Drivers of adoption of IPTi at the national level were the high mortality rate in infants, good efficacy data shown in early clinical trials, and the absence of a significant rainy season that prevented Sierra Leone from implementing SMC. These arguments were not sufficient for decision makers from the other countries included in our survey to decide to implement IPTi. The reasons for their reluctance ranged from fear of the emergence of resistance to SP, expected difficulties in synchronizing with the Expanded Programme on Immunization, unconvincing efficacy results, and gaps in coverage. These concerns are in line with the potential challenges identified and discussed in 2005 by O’Meara et al. . SeveralLastly, our survey provided some high-level information about the potential hurdles to the implementation of post-discharge malaria chemoprevention. Participants in our survey indicated that financial difficulties experienced by parents and poor adherence to treatments were two of the biggest issues they faced when treating patients under five years of age presenting with severe anemia. These two potential barriers will have to be addressed should PMC be implemented at a large scale, in addition to raising awareness about this intervention.The main limitation of the interviews with key informants was the small number of participants. Caution should be used when generalizing the results of this subset of respondents to the whole malaria prevention field. To mitigate the impact of the small sample size, we targeted participants who were the most influential and knowledgeable. The survey with field-level participants also presents a number of limitations. Regarding the sample size and composition, the total number of respondents per country was limited, and not all regions or districts were represented. Although we interviewed respondents from a mix of regions and settings to mitigate geographical bias, caution should be used when generalizing the results of this subset of respondents to the entire malaria-endemic region of sub-Saharan Africa. In terms of methodology, as with any survey, our findings reflect the answers and views of participants that may be influenced by their recall and response bias. To mitigate this risk, all key informants were interviewed by one person to achieve greater uniformity in interpretation. As for the interviews with field-level participants, clear guidance was provided to interviewers to ensure that they obtained the most accurate information. None of the interviewers had a pre-existing relationship with the survey participants. Several interviewers were used to administer the questionnaire in the different countries, which could result in some interviewer-based country variation. Importantly, all respondents answered the same questionnaire, and interviewers were trained to avoid this type of bias. All interviewers were professional market researchers having at least 10 years of experience in healthcare market research. They all hold a diploma in healthcare, public health, or pharmacy at the Master’s or PhD level. Despite these limitations, we believe that the data presented here are valuable, as they provide some qualitative input on the experience with and perception of malaria chemoprevention interventions, and they represent real-life data typically not obtainable on a large scale.This end user perspective study has provided new insights about the drivers and barriers for the adoption of various malaria chemoprevention interventions from the point of view of a select group of target respondents, key stakeholders, and end users. Wherever implemented, the chemoprevention interventions explored in our survey were perceived as valuable and efficacious in preventing malaria by survey participants. Logistical issues, such as staff shortages and out of stock situations, were identified as the biggest barrier to the full use of these interventions, highlighting the need for health system strengthening measures. Further expansions of these interventions, either to eligible geographies or broader age groups, could be envisaged, providing that health systems are able to absorb the increased workload and the provision of the sufficient drug is secured, that country-generated data on the positive impact of these interventions are available, and that the expansions are endorsed by normative bodies.