W1 - Intro to Stats Flashcards
List some parametric assumptions
Normal distribution of data
Homogeneity of variance
Linearity of association
What does the p value for parametric tests depend on?
normal sampling distribution.
What does Homogeneity of variance refer to?
Similarity in the variance throughout the data.
What shape is shown when the histogram of data is symmetrical with most frequent values around the middle point
Bell-shaped
What is meant by linearity of association
When the pattern of the dots on a scatterplot of 2 continuous measures are linear.
What type of parametric test is used when testing the difference between 2 means
Independent samples t-test
Paired samples t-test
What type of parametric test is used when testing the relationship between 2 continuous measures?
Pearsons correlation
What is the difference between parametric + non-parametric tests?
Parametric - Assumptions are met
Non-parametric - Assumptions NOT met
What non-parametric tests are used when testing the difference between 2 means
Mann-Whitney U-test
Wilcoxon Signed-rank test
What non-parametric test is used when testing the relationship between 2 continuous measures?
Spearman’s rank order correlation
What does the NONDIRECTIONAL alternative hypothesis state?
That there IS a difference between the mean scores of 2 groups but DOESN’T specify which group is expected to be larger or smaller.
Describe the difference between the SD and the SE (4 marks)
SD tells us how spread out the sample data is from the sample mean.
SE tells us how spread out the sample means are from the population mean.
List 3 threats to internal validity (3 marks)
No control group as changes could have occurred anyway.
Learning effects: participants get used to testing equipment so do better 2nd time.
Carry over effects: effects of 1st treatment are still present at time of starting 2nd treatment.
