Chi squared Flashcards
1
Q
What is the formula for chi squared?
A
x^2 = <sum> (O--E)^2/E</sum>
Where
O = observed
E = Expected
2
Q
What does the chi squared test do?
A
Used to test the null hypothesis
3
Q
What criteria is required for chi squared
A
Sample size must be over 20 - large
Data must be discrete
Only raw counts
4
Q
What is the null hypothesis
A
Hypothesis based on the assumption there is no significant difference between sets of observations and difference is due to chance alone.
5
Q
How are the degrees of freedom found?
A
Number of categories - 1
6
Q
What critical value do we use in chi squared?
A
0.05
7
Q
WHat happens if our chi squared value is MORE than 0.05?
A
Null hypothesis is accepted
8
Q
What happens if our chi squared value is LESS than 0.05?
A
Null hypothesis rejected
