Wright map (person-item map) — gg

Places the distribution of person estimates beside the item locations on the same latent scale, so you can see whether the test is targeted at the examinees. Polytomous items show each threshold.

Usage

gg_wright(x, method = "EAP", thresholds = TRUE, bins = 30)

Arguments

x: a unidimensional model returned by mirt::mirt().
method: scoring method for persons, passed to mirt::fscores().
thresholds: logical; plot every threshold of polytomous items rather than their average location.
bins: number of histogram bins for persons.

Value

A patchwork object (a combined ggplot).

Examples

mod <- mirt(Science, 1, verbose = FALSE)
gg_wright(mod)