Parametric Tests Inferential Analysis

Question 1

How to choose the correct statistical test

Answer 1

1) Is it a test of difference, a correlation or an association?
2) What design have I used? Independent measures or repeated measures/matched participants design?
3) What level of measurement have I used? Nominal, ordinal, interval, ratio?
4) Is the test non parametric or parametric?

Question 2

What are critical values

Answer 2

When working out the statistics for your research (by using one of the four statistical tests) you will compare your final result with a critical value. A critical value is a numerical value found in the statistical tables in the appendix that helps to determine the significance of your results. It can determine whether your results are significant or not – for instance is there a real difference between two conditions (if yes, then the results are significant and the experimental hypothesis should be accepted), or is the difference due to fluke or chance (if this is true, then we accept the null hypothesis).

Question 3

Related T-Test

Answer 3

• This is used when we wish to test a difference
• The design is repeated measures
• The data should be interval
• Related t-test is a parametric test

Question 4

Unrelated T-Test

Answer 4

• This test is used when we are looking for a test of difference
• This statistical test is used when we have an independent group design.
• This test has level of measurement which is interval.
• T unrelated t-test is a parametric test

Question 5

Pearson’s r

Answer 5

• This test is used for investigating correlations or relationships between variables
• The level of measurement for the data is interval
• Pearson’s r is a parametric test