Diffusion IRT Models for Response and Response Time Data
Conduct a likelihood ratio test on two nested diffIRT models
Return estimated parameters
Fitting diffusion IRT models
Estimating factor scores for diffIRT models
Assessing diffIRT model fit for the response times using QQ-plots
Assessing diffIRT model fit for the responses using limited informatio...
Simulate data according to the D-diffusion or Q-diffusion IRT model.
Simulate data according to the traditional diffusion model.
Summary function for diffIRT objects
Package to fit diffusion-based IRT models to response and response time data. Models are fit using marginal maximum likelihood. Parameter restrictions (fixed value and equality constraints) are possible. In addition, factor scores (person drift rate and person boundary separation) can be estimated. Model fit assessment tools are also available. The traditional diffusion model can be estimated as well.