item_restscore function

Item Restscore Association

The observed Gamma coefficient between the score of a single item and the total score of the remaining items is compared with the corresponding expected Gamma coefficient under the Rasch model.

item_restscore(
  object,
  p.adj = c("BH", "holm", "hochberg", "hommel", "bonferroni", "BY", "none")
)

Arguments

• object: An object of class "Rm", a fitted Rasch model or partial credit model using the functions RM or PCM in package eRm, or an object of class "pcmodel", a fitted partial credit model using the function pcmodel in package psychotools.
• p.adj: Correction method for multiple testing. The methods are "BH","holm", "hochberg", "hommel", "bonferroni", "BY", "none". See p.adjust.

Returns

a matrix containing: - observed: observed gamma coefficients

• expected: expected gamma coefficients

• se: standard errors

• pvalue: p values (under normal distribution assumption)

• padj: adjusted p values if selected

• sig: significance stars: 0 " *** " 0.001 " ** " 0.01 " * " 0.05 " . " 0.1 " " 1

Examples

rm.mod <- RM(amts[,4:13])
item_restscore(rm.mod)

References

Kreiner, S. (2011). A note on item-restscore association in Rasch models. Applied Psychological Measurement, 35, 557-561.

Author(s)

Marianne Mueller