The Item-Total Biserial Correlation computes the biserial correlation between each item and the total score. This function is applicable only to binary response data.
This correlation provides a measure of item discrimination, indicating how well each item distinguishes between high and low performing examinees.
ITBiserial(U, na = NULL, Z = NULL, w = NULL)# S3 method for default
ITBiserial(U, na = NULL, Z = NULL, w = NULL)
# S3 method for binary
ITBiserial(U, na = NULL, Z = NULL, w = NULL)
A numeric vector of item-total biserial correlations. Values range from -1 to 1, where:
Values near 1: Strong positive discrimination
Values near 0: No discrimination
Negative values: Potential item problems
Either an object of class "exametrika" or raw data. When raw data is given,
it is converted to the exametrika class with the dataFormat
function.
Values to be treated as missing values.
Missing indicator matrix of type matrix or data.frame. Values of 1 indicate observed responses, while 0 indicates missing data.
Item weight vector specifying the relative importance of each item.
# using sample dataset
ITBiserial(J15S500)
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