Calculation of the point biserial correlations for dicho- or polytomous item categories with total scale (person parameter).
Usage
ptbis(y, daten = NULL)
Value
An object of class c("data.frame", "ptbis") containing item statistics.
Arguments
y
either an object of class "pers", or an numeric vector as an result of any scaling approach (WLE, MLE, Rawscore, etc. ) relating to the Items (columns) in daten.
daten
if argument y is not an object of class "pers", a "data.frame", potentially with missing values, comprising dicho- or polytomous items (columns).