Chi Squared tests Flashcards
What is Chi-squared test of independence used for?
To compare proportions of successes in a categorical variable across groups of another categorical variable.
What are the features of the Chi-square distribution?
Degrees of freedom and non-centrality parameters.
If the features are large, what happens with the Chi-squared distribution?
Can be approximated by a normal distribution.
The Chi-squared test is a square number, so…
It is always non-negative, and only the right tail tends to be of interest.
The null hypothesis for the Chi-squared test of independence claims…
Independence across groups.
What is Chi-squared goodness of fit test used for?
To compare the proportions of a categorical variable to a hypothesized distribution.
The sample matches with the hypothesized distribution.
