# NURS341 Lecture Notes - Lecture 7: Dependent And Independent Variables, Test Statistic

## Document Summary

Decide based on level of measurement of variables. Chi-square requires: 2 independent samples, dependent variable measured at nominal or ordinal level, must have at least 5 cases per cell. Looking for a difference in sadness (dv) for people who experience conflict and those that do not (2 iv) How the chi-square test works: step 1. Plot observed frequencies (in other words, your data) in a table. This is defined as what you would have expected to observe if, in reality, there were no relationship between the variables of interest. Example: some conflict, sad = (2035 x 2020) / 4060. Some conflict, happy=(2035 x 2040) / 4060: step 3. Means sum: for each cell in the table, calculate observed - expected, square the result, divide by the expected value for that cell, then add the results from each cell. The result is your chi-square statistic: step 4: Calculate the degrees of freedom (#rows-1) x (#columns-1)