digram.person.p: Calculate probability of correct answer to item categories

In jeppebundsgaard/RDigram: Analysis of Items from Tests and Surveys

Calculate probability of correct answer to item categories

Description

Calculate probability of correct answer to item categories

Usage

digram.person.p(mod, item.params = NULL, thetas = NULL, ns = NULL)

Arguments

mod	A TAM or eRm model
item.params	Item params in PCM parametrization in a matrix or data.frame with categories in columns and persons in rows. If left out, item.params is taken from mod.
thetas	A vector of person parameters. If left out, thetas is calculated from the model. It takes time on large datasets.
ns	A vecor of the same length as thetas. Number of persons having each theta. If left out, it is counted from mod or set to 1.

Value

Returns a list of unique thetas, consisting of Theta, Npers (number of persons having this theta) and a data.frame of probabilities of getting points in the category.

Examples

mod<-digram.estimate(DHP)
p<-digram.person.p(mod)

jeppebundsgaard/RDigram documentation built on Oct. 29, 2023, 7:15 p.m.