dropPerfectScores: Drop subjects and items with all perfect scores

In cdriveraus/bigIRT: Fits item response theory models to big data

Drop subjects and items with all perfect scores

Description

This function drops variables/items and subjects that have all perfect scores (either all 0's or all 1's) in a data table.

Usage

dropPerfectScores(
  dat,
  scoreref. = "score",
  itemref. = "Item",
  idref. = "id",
  tol. = 0.001
)

Arguments

dat	The input data table
scoreref	The column name of the score variable in dat
itemref	The column name of the item variable in dat
idref	The column name of the id variable in dat
tol	Tolerance level for checking perfect scores – .01 would drop subjects with less than 1% correct or incorrect

Value

The input data table (dat) without variables/items and subjects with all perfect scores.

Examples

dat <- data.table(id=c(1,1,1,2,2,2,3,3,3), Item=c('I1','I2','I3','I1','I2','I3','I1','I2','I3'),
   score=c(1,0,1,0,0,0,0,1,1))
print(dropPerfectScores(dat))

cdriveraus/bigIRT documentation built on Sept. 14, 2024, 5:42 a.m.