Published online by Cambridge University Press: 01 January 2025
Using the well-known strategy in which parameters are linked to the sampling distribution via an identification analysis, we offer an interpretation of the item parameters in the one-parameter logistic with guessing model (1PL-G) and the nested Rasch model. The interpretations are based on measures of informativeness that are defined in terms of odds of correctly answering the items. It is shown that the interpretation of what is called the difficulty parameter in the random-effects 1PL-G model differs from that of the item parameter in a random-effects Rasch model. It is also shown that the traditional interpretation of the guessing parameter in the 1PL-G model changes, depending on whether fixed-effects or random-effects versions of both models are considered.
Electronic supplementary material The online version of this article (https://doi.org/10.1007/s11336-018-09659-w) contains supplementary material, which is available to authorized users.
The partial financial support of the ANILLO Project SOC1107 (ended in November 2015) from the Chilean Government is gratefully acknowledged. The first, second and third authors also acknowledge the partial financial support of FONDECYT Projects 11160374, 1150233 and 1181216, respectively.