Week 5: Chi-Squared Test Flashcards
What is the purpose of a chi-squared test?
To assess the independence between two categorical variables
What is H0 in a chi-squared test?
The variables are independent
When is the chi-squared test considered statistically significant?
When p < 0.05
How do you compute a chi-squared test?
<tabulate var1 var2, row col chi2>
What is the formula for degrees of freedom in a chi-squared test?
(No. of rows - 1) x (No. of columns - 1)
What does a significant chi-squared result imply?
Evidence to reject H0 and conclude a significant association
In research, how is the chi-squared test applied to test if pain experience is related to gender?
Cross-tabulate variables for gender and pain experience and compute χ2
How do you formally report results from chi-squared test?
A Pearson’s chi-squared test of independence was carried out to assess whether gender and frequent experience of pain are independent. Results (χ2
(1) = 10.68, p=0.001) suggest there is strong evidence to reject the null hypothesis of no independence between these two variables. Descriptive findings indicate that more women than men experience pain frequently
How do we compute a chi-squared test with three variables?
We need to create a three-way table
<bysort cat_variable: tabulate dependent_variable independent_variable, row col chi2>