Produces APA-style narrative text interpreting the results of a differential-
functioning analysis or interaction table. For method = "refit", the
report summarises the number of facet levels classified as negligible (A),
moderate (B), and large (C). For method = "residual", it summarises
screening-positive results, lists the specific levels and their direction,
and includes a caveat about the distinction between construct-relevant
variation and measurement bias.
Arguments
- dif_result
Output from
analyze_dff()/analyze_dif()(classmfrm_dffwith compatibility classmfrm_dif) ordif_interaction_table()(classmfrm_dif_interaction).- ...
Currently unused; reserved for future extensions.
Details
When dif_result is an mfrm_dff/mfrm_dif object, the report is based on
the pairwise differential-functioning contrasts in $dif_table. When it is an
mfrm_dif_interaction object, the report uses the cell-level
statistics and flags from $table.
For method = "refit", ETS-style magnitude labels are used only when
subgroup calibrations were successfully linked back to a common baseline
scale; otherwise the report labels those contrasts as unclassified because
the refit difference is descriptive rather than comparable on a linked
logit scale. For method = "residual", the report describes
screening-positive versus screening-negative contrasts instead of applying
ETS labels.
Interpreting output
$narrative: character scalar with the full narrative text.$counts: named integer vector of method-appropriate counts.$large_dif: tibble of large ETS results (method = "refit") or screening-positive contrasts/cells (method = "residual").$config: analysis configuration inherited from the input.
Typical workflow
Run
analyze_dff()/analyze_dif()ordif_interaction_table().Pass the result to
dif_report().Print the report or extract
$narrativefor inclusion in a manuscript.
Examples
toy <- load_mfrmr_data("example_bias")
fit <- fit_mfrm(toy, "Person", c("Rater", "Criterion"), "Score",
method = "JML", model = "RSM", maxit = 25)
diag <- diagnose_mfrm(fit, residual_pca = "none")
dif <- analyze_dff(fit, diag, facet = "Rater", group = "Group", data = toy)
rpt <- dif_report(dif)
cat(rpt$narrative)
#> DRF screening was conducted for the Rater facet across levels of Group using the residual method. A total of 4 pairwise facet-level comparisons were evaluated. 0 comparison(s) were screening-positive and 4 were screening-negative based on the residual-contrast test.
#> No pairwise contrasts were screening-positive under the residual-screening method. This does not by itself establish invariance or consistent functioning across groups.
#> Note: The presence of differential functioning does not necessarily indicate measurement bias. Differential functioning may reflect construct-relevant variation (e.g., true group differences in the attribute being measured) rather than unwanted measurement bias. Substantive review is recommended to distinguish between these possibilities (cf. Eckes, 2011; McNamara & Knoch, 2012).