lecture 2 - chi squared and t test

Question 1

tests which measure bivariate relationships

Answer 1

chi squared

2 sample t test

Question 2

what does chi squared do

Answer 2

measures the difference between observed and expected values if there is no pattern / tells you if there is a pattern or just random

Question 3

variables in chi squared

Answer 3

categorical - cannot be scalar

Question 4

what is a contingency table?

Answer 4

a type of table that displays the frequency distribution of the variables

Question 5

what does chi squared NOT do?

Answer 5

tells you what the pattern in the data is

Question 6

the result is significant if the chi squared output is equal to or more than…?

Answer 6

5

Question 7

how to calculate the expected value

Answer 7

(row total * column total) / grand total

Question 8

requirements

Answer 8

each respondent can only be in one cell

each cell must have an expected value more than 5

Question 9

what is a binary variable

Answer 9

variable that only takes 2 values e.g. male and female

Question 10

what does a 2 sample t-test do?

Answer 10

assesses whether the means of 2 groups are statistically significant from each other

Question 11

what variables are needed for a t test?

Answer 11

categorical - binary variable

scalar

Question 12

what are the assumptions for a 2 sample t test?

Answer 12

1. population needs to be normally distributed
2. if population is not normally distributed, a large sample size is needed
3. homogeneity of variance - same amount of variation in each of the 2 groups is similar
4. cannot be carried out if the 2 groups are small and non-parametric