Data of 1000 respondents working on a multistage test using a (1,2,2) design. The responses were generated based on the 2PL model. Each module consists of 7 items. Data were generated using the mstR package, version 1.2 (https://cran.r-project.org/web/packages/mstR/index.html).
A list with 7 elements:
The response matrix, with rows corresponding to respondents and columns corresponding to items.
A matrix of item parameters. The columns contain the discrimination, difficulty, pseudo-guessing and inattention parameters of the 4PL models. The discrimination parameters were drawn from a N(1,0.2) distribution. The difficulty parameters were drawn from normal distributions. For module 1 (items 1-7), this distributions was N(0,1), for modules 2 and 4 (items 8-14 and 22-28) it was N(1,1) and for modules 3 and 5 (items 15-21 and 29-35) the distribution was N(-1,1).
The true ability parameters.
The ability parameters estimated by the WLE estimator.
A simulated categorical person covariate. The first 500 respondents belong to group 0, the remaining 500 respondents to group 1.
A simulated continuous person covariate. It simulates an age covariate, with a uniform distribution between 20 and 60.
The standard errors of the estimated ability parameters.
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