Chi Squared

Question 1

When should you use Chi Squared?

Answer 1

Categorical Variables

Question 2

What does Chi Squared measure?

Answer 2

the significance of the observed association amongst variables

Question 3

What is asscociation?

Answer 3

• The degree of dependency between two variables X and Y
• Or: How much is variation in X related to variation in Y?
• Or: Does knowing the value of X give you any help in predicting Y’s value?
• e.g.: Does knowing X (sex) = male, help us predict Y (opinion on drug policy)?

Question 4

How is Association between/among categorical data displayed?

Answer 4

Contingency tables - displays the data in rows and columns, to display number of observations for each category of each variable.

Question 5

What steps should you take to peform a chi squared?

Answer 5

1. Sum all rows and column of contingency table in both directions (observed data)
2. Calculate the expected frequencies under null (if there were no differences)
3. Calculate the chi-squared
4. Calculate degrees of freedom

Question 6

How do you calculate degrees of freedom for Chi Squared?

Answer 6

DF = (rows-1)*(columns-1)

Question 7

When would you reject the null hypothesis?

Answer 7

When the value of C-squared is higher than the critical value

Question 8

What is the p-value called on a chi sqaured SPSS output?

Answer 8

Asymp. Sig.

Question 9

When would be reject the null hypothesis using Asymp. Sig. in the SPSS output?

Answer 9

If it is below 0.05

Question 10

What are Phi and Cramers V

Answer 10

values which explore the association between categorical (nominal-nominal or nominal-ordinal) variables