Elham Pakrad, Keyvan Salehi, Rob Meijer, Balal Izanloo, Ali Moghadamzadeh,
Volume 21, Issue 3 (9-2023)
Abstract
Background and Objectives: Various factors can play a role in producing aberrant response. The presence of aberrant response has a significant effect on the validity of the test. If the test scores do not have adequate validity, the score does not reflect the true latent trait of the test. Individual person fit statistics are indicators for evaluating the compatibility of test scores with a certain measurement model or with a group of examinees. This research was conducted with the aim of investigating how to compute the person fit statistics of the biology course of the 2022 university entrance exam using the PerFit package in the R software.
Materials and Methods: In this descriptive study, the answer sheets of 1000 candidates aged 16 to 18 years of the national exam who answered 50 items in the biology course were examined. To compute individual person fit statistics, PerFit package was used in R software. Also, a number of its functions were also examined.
Results: The commands for compute individual person fit statistics, and were presented and the values of these statistics were calculated.
Conclusion: The PerFit package was introduced as a powerful tool for measuring individual person fit and it was shown that the individual person fit statistics can be easily used for academic achievement tests using this package.
