A2 statistical tests

Question 1

Describe a Mann-Whitney U Test

Answer 1

• Test of difference
• Used with ordinal, interval or ratio data
• Used with an independent groups design
• Observed value should be equal to or less than the critical value to reject the null hypothesis

Question 2

Using a Mann-Whitney U test, how would you know you could reject the null hypothesis

Answer 2

Observed value should be equal to or less than the critical value

Question 3

What test can be used on Independent groups (potentially a second also…)

Answer 3

Mann-Whitney U

Chi Squared

Question 4

Which 3 of the 4 tests can be used on interval, ordinal or ratio data?

Answer 4

Mann-Whitney U
Wilcoxin T
Spearman’s Rank Order Correlation

Question 5

Which test is for use on nominal data?

Answer 5

Chi Squared

Question 6

Describe the Wilcoxin T test

Answer 6

• Test of difference
• The data should be ordinal, interval or ratio
• It is used with a repeated measures design or a matched pairs
• Observed value should be equal to or less than the critical value to reject the null hypothesis

Question 7

Using a Wilcoxin T test, how can we reject our null hypothesis?

Answer 7

The observed value should be equal to or less than the critical value in order to reject the null hypothesis

Question 8

Describe a Chi Squared test

Answer 8

• This is a test of association (difference) when data is nominal
• It cannot be used with data or averages
• The data must be independent - something recorded in one category cannot be recorded in another
• Used on nominal data
• Observed value should be greater than the critical value to reject the null hypothesis

Question 9

How can we reject a null hypothesis using a Chi Squared test?

Answer 9

The observed value must be greater than the critical value to reject the null hypothesis

Question 10

Describe the Spearman’s Rank Order Correlation

Answer 10

• Used when testing for correlation with pairs of scores
• The data should be ordinal, interval or ratio
• The test gives a correlation coefficient with a value between +1.00 and -1.00
• The sign indicates the direction of the relationship (positive or negative)
• The number indicates the strength of correlation
• Observed value should be equal to or more than the critical value to reject the null hypothesis

Question 11

How can we reject a null hypothesis using a Spearman’s Rank order Correlation test?

Answer 11

The observed value must be more than or equal to the critical value to reject the null hypothesis

Question 12

When understanding how to interpret results of a statistical test by using a table of critical values, what si it important to know?

Answer 12

It is a one tailed test for a directional hypothesis

Two tailed test for a non-directional hypothesis