factor_score {IRTest}

Estimated factor scores

Description

Factor scores of examinees.

Usage

factor_score(x, ability_method = "EAP", quad = NULL, prior = NULL)

Arguments

x

A model fit object from either IRTest_Dich, IRTest_Poly, IRTest_Cont, or IRTest_Mix.

ability_method

The ability parameter estimation method. The available options are Expected a posteriori (EAP) and Maximum Likelihood Estimates (MLE). The default is EAP.

quad

A vector of quadrature points for EAP calculation.

prior

A vector of the prior distribution for EAP calculation. The length of it should be the same as quad.

Value

theta

The estimated ability parameter values. If ability_method = "MLE". If an examinee receives a maximum or minimum score for all items, the function returns \pmInf.

theta_se

The standard errors of ability parameter estimates. It returns standard deviations of posteriors for EAPs and asymptotic standard errors (i.e., square root of inverse Fisher information) for MLE. If an examinee receives a maximum or minimum score for all items, the function returns NA for MLE.

Author(s)

Seewoo Li [e-mail]

Examples

# A preparation of dichotomous item response data

data <- DataGeneration(N=500, nitem_D = 10)$data_D

# Analysis

M1 <- IRTest_Dich(data)

# Item fit statistics

factor_score(M1, ability_method = "MLE")