Revise later
SpaceTo flip
If confident
All Flashcards
Explain the concept of homogeneity in the context of chi-squared tests.
Tests if different populations are similar in their distribution of a categorical variable.
Explain the concept of independence in the context of chi-squared tests.
Tests if two variables are not associated with each other.
Explain the purpose of calculating expected counts.
To determine what the cell values would be if there is no association between the variables.
What is the formula for calculating expected counts in a two-way table?
Expected Count = (Row Total * Column Total) / Table Total
What is the formula for the Chi-Squared Test Statistic?
$$\chi^2 = \sum \frac{(Observed - Expected)^2}{Expected}$$
What is the formula for calculating degrees of freedom in a Chi-Squared Test?
$$df = (number\ of\ rows - 1) * (number\ of\ columns - 1)$$
What are the differences between the Chi-Squared Test for Homogeneity and the Chi-Squared Test for Independence?
Homogeneity: Compares across populations, looking for similar distributions. | Independence: Looks within a single population, testing for associations between variables.
Compare and contrast the null hypothesis for the Chi-Squared Test for Homogeneity and Independence.
Homogeneity: The distribution of the categorical variable is the same across all populations. | Independence: There is no association between the two categorical variables.