ItemOdds {exametrika} | R Documentation |
Item Odds
Description
Item Odds are defined as the ratio of Correct Response Rate to Incorrect Response Rate:
O_j = \frac{p_j}{1-p_j}
where p_j
is the correct response rate for item j.
This function is applicable only to binary response data.
The odds value represents how many times more likely a correct response is compared to an incorrect response. For example, an odds of 2 means students are twice as likely to answer correctly as incorrectly.
Usage
ItemOdds(U, na = NULL, Z = NULL, w = NULL, ...)
Arguments
U |
U is a data matrix of the type matrix or data.frame. |
na |
na argument specifies the numbers or characters to be treated as missing values. |
Z |
Z is a missing indicator matrix of the type matrix or data.frame |
w |
w is item weight vector |
... |
Internal parameters for maintaining compatibility with the binary data processing system. Not intended for direct use. |
Value
A numeric vector of odds values for each item. Values range from 0 to infinity, where:
odds > 1: correct response more likely than incorrect
odds = 1: equally likely
odds < 1: incorrect response more likely than correct
Note
This function is implemented using a binary data compatibility wrapper and will raise an error if used with polytomous data.
Examples
# using sample dataset
ItemOdds(J5S10)