Show simple Classical Test Analysis statistics at item and test level
a connection to a dexter database, a matrix, or a data.frame with columns: person_id, item_id, item_score
An optional expression to subset data, if NULL all data is used
How to present the item level statistics: raw
for each test booklet
separately, averaged
booklets are ignored, with the exception of rit and rir which are averaged over the test booklets,
with the number of persons as weights, or compared
, in which case the pvalues,
correlations with the sum score (rit), and correlations with the rest score (rit) are
shown in separate tables and compared across booklets
use the observed maximum item score or the theoretical maximum item score according to the scoring rules in the database to determine pvalues and maximum scores
add a tia for distractors, only useful for selected response (MC) items
A list containing:
a data.frame of statistics at booklet level
a data.frame (or list if type='compared') of statistics at item level
a data.frame of statistics at the response level (if distractor==TRUE), i.e. rvalue (pvalue for response) and rar (rest-alternative correlation)