Plot person fit — plot_person

Person locations against a person fit statistic with the +/- 2.5 band; persons beyond the band respond erratically (positive) or too deterministically (negative). The default statistic is the log-of-mean-square fit residual; "infit" and "outfit" display the Wilson–Hilferty standardised mean squares, to which the same band convention applies.

Usage

plot_person_fit(fit, statistic = c("residual", "infit", "outfit"), band = 2.5)

Arguments

fit: A fitted object from rasch.
statistic: "residual" (the default fit residual), "infit", or "outfit".
band: Acceptance band for the standardised statistic.

Value

Called for its plotting side effect; invisibly NULL.

Examples

set.seed(1)
d <- seq(-2, 2, length.out = 6)
X <- matrix(rbinom(400 * 6, 1, plogis(outer(rnorm(400), d, "-"))), 400, 6)
colnames(X) <- paste0("I", 1:6)
plot_person_fit(rasch(X))