ANOVA TESTS Flashcards
Define an indepdent t-test?
Parametric test for a between subject design
Define paired samples t-test?
Parametric test for a within subject design
Define the Mann-Whitney u test?
Non-parametric test for a between subject design
Define the wilcoxon test?
Non-parametric test for a within subject design
Whats an example of a research questions where we would want three or more conditions?
Sluckin et al
Explain sluckin et Al’s study?
Relationship between liking and familiarity is best described as an inverted u
- manipulation don’t always have linear effects
- if we only had two conditions we would draw incorrect conclusions about the phenomenon
What increases when we use multiple t-tests?
Type 1 errors which are false positives
- since each test has a 1/20 probability of getting a significant result when there isn’t one
If you conduct several tests on a single dataset, it increases the likelihood of hitting the 1/20 chance
What happens when you have 4 conditions?
U need to conduct 6 tests
What happens when theres 4 conditions?
You need to conduct 6 t-tests
Whats the chances of having at least one type of 1 error for when the conditions are 4?
20%
Give an example of a study with multiple conditions?
The dead fish study by bennet et al
Explain the dead fish study by bennet et al?
FMRI study where participants were required to undergo a persepective task - see a photo of different social situations and determine the emtions of the individual in the photo
Whats the analyse of the dead fish study?
The brain was divided inot voxels and t-tests were run that compared activation when viewing photos verses rest
- a lot of t-tests were run
What was the brains activity like in the dead fish study?
Significant increase in activatoion observed within some areas of the salmons brain cavity when viewing photos compared to rest
What does anova do?
Examines differences between three or more levels of an indepdent variable
More specifically it tests the null hypothesis that the populations from which the samples have been drawn have equal means
Examples of when to use one way anova?
- comparing blood oxygen levels between three groups = smokers, people who never smocked and former smokers
- comparing scores on a spelling test between children who attend five different schools
List the criteria of using one -way anova?
- examining three or more levels of an indepdent variable
- data is interval or ratio
- study is between subject
Explain about the only using one way anova when it’s examining a difference between three or more levels of an indepdent variable?
Levels of the independent variable are the different values of the indepdent variable v
