Inferential tests Flashcards
Why are statistical tests used in psychological research?
Statistical tests are used to determine the likelihood that the effect they have found is due to chance by allowing a significance level to be determined.
What do statistical tests for correlations give us?
A correlation coefficient
calculated value
What is a one-tailed hypothesis?
A directional hypothesis
What is a two-tailed hypothesis?
A non-directional hypothesis
What is the sign test?
- A test of difference
- Use it for nominal data
- Used to analyse repeated measures or matched pairs design (related)
How do you carry out the sign test?
- For each participant, note whether the sign is +, - or = depending on whether the score in each condition goes down, up or stays the same.
- Count N, which is the number of participants, excluding those with equal (=) scores.
- Count the number of the least frequent sign (- or +).
- This is s.
- Use the sign test table
- See whether the results are significant by seeing the number of N, whether the hypothesis is 1 or 2 tailed and at what level of significance it is at.
What test is used if:
- It is a test of difference
- It is unrelated
- It uses nominal data?
Chi-squared
What test is used if:
- It is a test of difference
- It is related
- It uses nominal data?
Sign test
What test is used if:
- It is a test of difference
- It is unrelated
- It uses ordinal data?
Mann-Whitney
What test is used if:
- It is a test of difference
- It is related
- It uses ordinal data?
Wilcoxon
What test is used if:
- It is a test of difference
- It is unrelated
- It uses interval data?
Unrelated t-test
What test is used if:
- It is a test of difference
- It is related
- It uses interval data?
Related t-test
What test is used if:
- It is a test of correlation
- It uses nominal data?
Chi-squared
What test is used if:
- It is a test of correlation
- It uses ordinal data?
Spearman’s rho
What test is used if:
- It is a test of correlation
- It uses interval data?
Pearson’s r
