Create item inclusion tuples from item stem.

If item-stimulus hierarchies are stored in a single stimulus column, stemInclusionTuples transforms this format into item pairs ('tuples').

Usage

stemInclusionTuples(items, idCol = "ID", stemCol)

Arguments

items

A data.frame with information on an item pool.

idCol

character or integer indicating the item ID column in items.

stemCol

A column in items containing the item stems or stimulus names, shared among items which should be in the same test form.

Value

A data.frame with two columns.

Details

Inclusion tuples can be used by itemInclusionConstraint to set up inclusion constraints.

Examples

# Example data.frame
inclDF <- data.frame(ID = paste0("item_", 1:6),
          stem = c(rep("stim_1", 3), "stim_3", "stim_4", "stim_3"),
          stringsAsFactors = FALSE)

# Create tuples
stemInclusionTuples(inclDF, idCol = "ID", stemCol = "stem")
#>      [,1]     [,2]    
#> [1,] "item_1" "item_2"
#> [2,] "item_1" "item_3"
#> [3,] "item_2" "item_3"
#> [4,] "item_4" "item_6"