Calculation of the point biserial correlations for dicho-
or polytomous item categories with total scale (person
parameter).
Usage
ptbis(y, daten = NULL)
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).
Value
An object of class "data.frame" and "ptbis" containing
item statistics.