SPHERE has developed many Stata commands in psychometrics field. These commands are made available on the PRO-online project website. This project aims at proposing to students or researchers a way to perform analyses in the field of Classical Test or Item Response Theories on their own data, in a user-friendly manner, without complex handling of the data.
Rasch Measurement Theory
- raschtest : Estimation of the parameters of a Rasch model, computation of fit tests and creation of specific graphs.
- pcm : Estimation of the parameters of the Partial Credit Model and creation of graphs.
Non-parametric IRT
- loevh : Estimation of Loevinger's H coefficients and nonparametric Item Responses Models
Response-shift detection
- rsoort : Identification of response shift based on Structural Equation Modeling
- rosali : Identification of response shift at item-level based on Rasch
Scale validation
- validscale : Assessment of the validity and reliability of a multidimensional measurement scale
Power and sample size
- raschpower : Estimation of the power of the Wald test in the context of the Rasch model or the Partial Credit Model: comparison of the means of two groups of patients (cross-sectional) or the means of one group of patients between two times of measurement (longitudinal)
Items selection
- MSP : Mokken scale procedure (Automated Item Selection Procedure)
- CLV : Clustering around Latent Variables
- HCAvar : Hierarchical Cluster Analysis of Variables
Simulation
- simirt : Simulation of IRT models
Other
- sf36fr : Computation of the SF-36 scores