Conditional Item Characteristic Curves — RIciccPlot • easyRasch

A wrapper function to simplify getting CICC curves from iarm::ICCplot() for any number of items in the same figure. Uses the patchwork package, which also allows for further additions to a plot using for instance:

Usage

RIciccPlot(data, class_intervals = 5, method = "cut", dif = "no", dif_var = NA)

Arguments

data: Dataframe/tibble with only item response data coded as integers
method: Either "cut" (default) or "score" for all possible total scores
dif: Defaults to "no". Needs a defined dif_var if set to "yes"
dif_var: An exogenous variable (ie. age group, sex) coded as a factor
classintervals: Number of groups to divide respondents into

Details

+ plot_annotation(subtitle = "Some subtitle"). See ?plot_annotation for more possibilities.

A useful option is for DIF analysis, which requires two optional settings: dif = "yes" and dif_var = your$difvariable.

Text from ?iarm::ICCplot:

Plots Item Characteristic Curves for dichotomous and polytomous items using average scores within adjacent class intervals (method="cut").