ItemReport {exametrika} | R Documentation |
Generate Item Report for Non-Binary Test Data
Description
Calculates item-level statistics for non-binary test data, including response rates, basic descriptive statistics, and item-total correlations.
Usage
ItemReport(U, na = NULL, Z = NULL, w = NULL)
Arguments
U |
Either an object of class "exametrika" or raw data. When raw data is given,
it is converted to the exametrika class with the |
na |
Values to be treated as missing values |
Z |
Missing indicator matrix of type matrix or data.frame. Values of 1 indicate observed responses, while 0 indicates missing data. |
w |
Item weight vector specifying the relative importance of each item |
Details
This function is intended for non-binary (ordinal or rated) response data. It provides detailed statistics for each item in the test, focusing on response patterns and the relationship between individual items and overall test performance. If binary data is provided, an error message will be displayed.
Value
An object of class "exametrika" and "QitemStatistics" containing:
- ItemLabel
Labels identifying each item
- Obs
Number of valid responses for each item
- ObsRatio
Proportion of valid responses for each item (range: 0-1)
- ItemMean
Mean score of each item
- ItemSD
Standard deviation of each item score
- ItemCORR
Item-total correlation coefficients - correlation between item scores and total test scores
- ItemCORR_R
Corrected item-total correlation coefficients - correlation between item scores and total test scores excluding the target item
Examples
# Generate item report for sample ordinal data
item_stats <- ItemReport(J15S3810)
# View first few rows of the item report
head(item_stats)
# Example with rated data including custom missing value indicator
item_stats2 <- ItemReport(J35S5000, na = -99)