The Chi-squared Test

Question 0

What does a null hypothesis assume?

Answer 0

That there is no significant difference between observed and expected results

Question 1

What is the formula used for the chi-squared test?

Answer 1

X^2 = total (O - E)^2
—————–
E

O - observed
E - expected

Question 2

How do you find the critical value?

Answer 2

• degrees of freedom (no. categories - 1)
• probability 0.05
• read off value

Question 3

What happens if x^2 is smaller than the critical value?

Answer 3

• we accept the null hypothesis
• there is no significant difference between your results and what you expected
• any difference is due to chance

Question 4

What happens if x^2 is greater than the critical value?

Answer 4

• reject the null hypothesis
• there is a significant difference between your results and the expected results
• the difference did not happen by chance