fitted: S3 Methods: fitted

In ForceChoice: Forced-Choice Modeling Based on Item Response Theory and Cognitive Diagnostic Models

S3 Methods: fitted

Description

Extract model-implied response probabilities from fitted ForceChoice model objects. Returns the conditional probability of each observed response given each person's estimated latent trait \hat{\boldsymbol{\theta}}_j, evaluated via the model's response function.

Usage

## S3 method for class 'MIRT'
fitted(object, ...)

## S3 method for class 'MGPCM'
fitted(object, ...)

## S3 method for class 'MGGUM'
fitted(object, ...)

## S3 method for class 'FCMIRT'
fitted(object, ...)

## S3 method for class 'FCDCM'
fitted(object, ...)

## S3 method for class 'FCGDINA'
fitted(object, ...)

## S3 method for class 'FCGGUM'
fitted(object, ...)

## S3 method for class 'TIRT'
fitted(object, ...)

Arguments

object	A fitted model object of class "MIRT", "MGPCM", "MGGUM", "FCMIRT", "FCDCM", "FCGDINA", "FCGGUM", or "TIRT".
...	Additional arguments (currently ignored).

Details

For binary-response models, each entry is the endorsement probability P(Y_{ij}=1 \mid \hat{\boldsymbol{\theta}}_j). For polytomous models, probabilities are returned in stacked format (one column per category). For forced-choice models, each entry is the probability of the observed ranking pattern in the given block.

Value

A numeric matrix of model-implied probabilities. Dimensions:

• Binary models (MIRT, TIRT): N \times I

• Polytomous models (MGPCM, MGGUM): N \times \sum K_i (stacked category probabilities)

• Forced-choice models (FCMIRT, FCGDINA, FCGGUM): N \times \sum K_b (block-pattern probabilities)

• FCDCM: N \times B (marginal block-choice probabilities after integrating over 2^D attribute patterns)

Methods (by class)

• fitted(MIRT): Fitted probabilities for MIRT objects. Returns N \times I matrix of endorsement probabilities.

• fitted(MGPCM): Fitted probabilities for MGPCM objects. Returns stacked category probability matrix.

• fitted(MGGUM): Fitted probabilities for MGGUM objects.

• fitted(FCMIRT): Fitted probabilities for FCMIRT objects. Returns block-pattern probability matrix.

• fitted(FCDCM): Fitted probabilities for FCDCM objects. Returns N \times B matrix of marginal block-choice probabilities after integrating over 2^D attribute patterns.

• fitted(FCGDINA): Fitted probabilities for FCGDINA objects. Returns block-pattern probability matrix after integrating over posterior attribute classes.

• fitted(FCGGUM): Fitted probabilities for FCGGUM objects.

• fitted(TIRT): Fitted probabilities for TIRT objects. Returns N \times I_{pairs} matrix of pairwise comparison probabilities.

ForceChoice documentation built on Sept. 13, 2026, 1:06 a.m.