A heteroscedastic generalized linear model with a non-normal speed factor for responses and response times.
In generalized linear modelling of responses and response times, the observed response time variables are commonly transformed to make their distribution approximately normal. A normal distribution for the transformed response times is desirable as it justifies the linearity and homoscedasticity assumptions in the underlying linear model. Past research has, however, shown that the transformed response times are not always normal. Models have been developed to accommodate this violation. In the present study, we propose a modelling approach for responses and response times to test and model non-normality in the transformed response times. Most importantly, we distinguish between non-normality due to heteroscedastic residual variances, and non-normality due to a skewed speed factor. In a simulation study, we establish parameter recovery and the power to separate both effects. In addition, we apply the model to a real data set.
['Molenaar|Dylan|D|http://orcid.org/0000-0002-7168-3238', 'Bolsinova|Maria|M|']
D006801:Humans D016014:Linear Models D008954:Models, Biological D015233:Models, Statistical D016011:Normal Distribution D011930:Reaction Time
heteroscedasticity non-normality factor analysis item response theory non-linearity response time modelling