calculate_posterior {dscore}

Calculate posterior of ability

Description

If the tauj is not within the range rello - relhi from the dynamic EAP, the procedure ignores the score of item j.

Usage

calculate_posterior(scores, tau, qp, scale, mu, sd, relhi, rello)

Arguments

scores

A vector with PASS/FAIL observations. Scores are coded numerically as pass = 1 and fail = 0.

tau

A vector containing the item difficulties for the item scores in scores estimated from the Rasch model in the preferred metric/scale.

qp

Numeric vector of equally spaced quadrature points.

scale

Scale expansion

mu

Numeric scalar. The mean of the prior.

sd

Numeric scalar. Standard deviation of the prior.

relhi

Positive numeric scalar. Upper end of the relevance interval

rello

Negative numeric scalar. Lower end of the relevance interval

Value

A list with three elements:

Name	Label
eap	Mean of the posterior
gp	Vector of quadrature points
posterior	Vector with posterior distribution.

Since ⁠dscore V40.1⁠ the function does not return the "start" element.

Author(s)

Stef van Buuren, Arjan Huizing, 2020