plot_residual_qq: Normal quantile-quantile plot of person standardized...

In mfrmr: Estimation and Diagnostics for Many-Facet Measurement Models

Normal quantile-quantile plot of person standardized residuals

Description

Produces a Q-Q plot of per-person standardized residuals. Under the fitted Rasch-family model the residuals are approximately N(0, 1), so deviations from the reference line diagnose distributional misfit that mean-square summaries may miss.

Usage

plot_residual_qq(
  fit,
  diagnostics = NULL,
  preset = c("standard", "publication", "compact", "monochrome"),
  draw = TRUE
)

Arguments

fit	An mfrm_fit.
diagnostics	Optional diagnose_mfrm() output; required entries are generated internally when absent.
preset	Visual preset.
draw	If TRUE, draw with base graphics.

Value

An mfrm_plot_data object with a data slot containing Person, Theoretical, Sample columns.

Examples

toy <- load_mfrmr_data("example_core")
fit <- fit_mfrm(toy, "Person", c("Rater", "Criterion"), "Score",
                method = "JML", maxit = 30)
p <- plot_residual_qq(fit, draw = FALSE)
head(p$data$data)
# Look for: points hugging the y = x reference line. Heavy upper-
#   right tails indicate persons whose residual aggregates exceed
#   the standard normal expectation; pair with `plot_unexpected()`
#   for case-level follow-up. This is an exploratory screen; do
#   not treat tail behaviour as a definitive normality test.

mfrmr documentation built on June 13, 2026, 1:07 a.m.