The dataframe containing the variables (items, questions) of interest.

items

Optionally, the variables (items, questions) of interest. If omitted, all variables (items, questions) in the dataframe will be used.

itemDiagnostics

Whether to also display the item diagnostics (specifically, the corrected item-total correlation, mean and variance excluding each item, and the reliability coefficients excluding each item).

digits

The number of digits to use when displaying the results.

# NOT RUN {## (Not run to test because it takes a long time.)
data(testRetestSimData);
reliability(testRetestSimData[, 2:11], itemDiagnostics = TRUE);
# }