Extended Models

This page introduces several extended models of the latent rank theory (LRT) / neural test theory (NTT).

Although the item category reference profile (ICRP) expressing the statistical characteristics of each item category, is mainly introduced here, the test reference profile (TRP), latent rank distribution (LRD), rank membership profile (RMP), rank membership distribution (RMD), and observation ratio profile (ORP) described on the “Features” page can be also obtained by analysis using polytomous LRT models.

The Bayesian estimation method, a monotonically increasing constraint, and missing data treatment can be implemented in the statistical learning process of polytomous LRT models. Additionally, test equating can be performed using polytomous models.

Graded Latent Rank Model

The graded latent rank (LRT) model or the graded neural test (GNT) model is an LRT/NTT model for analyzing ordered polytomous data. It is useful for analyzing testlet items and Likert-type variables of psychological questionnaires. This model reduces the dichotomous LRT model when the number of categories is two.

These example boundary category reference profiles (BCRPs) of the GLR model that are useful for reviewing the behavior of the probability of selecting each item category or higher category through the latent rank scale. A monotonically increasing constraint can be imposed on the BCRPs.

These example item category reference profiles (ICRPs) of the GLR model express the probability of selecting each item category. They show that examinees in higher latent ranks generally select higher categories.

Nominal Latent Rank Model

The nominal latent rank (NLR) model or the nominal neural test (NNT) model is a polytomous LRT/NTT model for analyzing nominal-polytomous data. The NLR model is used for evaluating the statistical feature for incorrect choices of multiple-choice items. This model reduces the dichotomous LRT model when the number of categories is two.

These are example ICRPs of the NLR model. The profiles with red numbers are the correct-answer ones. The lines labeled “x” represent the merger of categories for which the selection ratios were less than 10% for examinees. These plots show that the ICRPs for the correct answers increase with the latent rank. The monotonically increasing constraint can also be imposed on the ICRPs for the correct answers. The ICRPs of the NLR model can clarify the statistical characteristics of the analyzed items, for example, the existence of attractive incorrect choices for examinees in lower latent ranks or the existence of items with virtually two alternatives.

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