Skip to contents

Build an anchor table from fitted estimates

Source: R/api-estimation.R
make_anchor_table.Rd

Build an anchor table from fitted estimates

Usage

make_anchor_table(fit, facets = NULL, include_person = FALSE, digits = 6)

Arguments

fit

Output from fit_mfrm().

facets

Optional subset of facets to include.

include_person

Include person estimates as anchors.

digits

Rounding digits for anchor values.

Value

A data.frame with Facet, Level, and Anchor.

Details

This function exports estimated facet parameters as an anchor table for use in subsequent calibrations. This is the standard approach for linking across administrations: a reference run establishes the measurement scale, and anchored re-analyses place new data on that same scale.

Anchor values should be exported from a well-fitting reference run with adequate sample size. If the reference model has convergence issues or large misfit, the exported anchors may propagate instability. Re-run audit_mfrm_anchors() on the receiving data to verify compatibility before estimation.

The digits parameter controls rounding precision. Use at least 4 digits for research applications; excessive rounding (e.g., 1 digit) can introduce avoidable calibration error.

Interpreting output

  • Facet: facet name to be anchored in later runs.

  • Level: specific element/level name inside that facet.

  • Anchor: fixed logit value (rounded by digits).

Typical workflow

  1. Fit a reference run with fit_mfrm().

  2. Export anchors with make_anchor_table(fit).

  3. Pass selected rows back into fit_mfrm(..., anchors = ...).

See also

fit_mfrm(), audit_mfrm_anchors()

Examples

toy <- load_mfrmr_data("example_core")
fit <- fit_mfrm(toy, "Person", c("Rater", "Criterion"), "Score", method = "JML", maxit = 25)
anchors_tbl <- make_anchor_table(fit)
head(anchors_tbl)
#> # A tibble: 6 × 3
#>   Facet     Level         Anchor
#>   <chr>     <chr>          <dbl>
#> 1 Criterion Accuracy      0.248 
#> 2 Criterion Content      -0.414 
#> 3 Criterion Language      0.0969
#> 4 Criterion Organization  0.0690
#> 5 Rater     R01          -0.196 
#> 6 Rater     R02          -0.329 
summary(anchors_tbl$Anchor)
#>       Min.    1st Qu.     Median       Mean    3rd Qu.       Max. 
#> -4.142e-01 -2.290e-01  8.296e-02 -1.300e-07  2.053e-01  3.335e-01