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:

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)

[Package exametrika version 1.1.0 Index]