Bivariate Flashcards
(14 cards)
What is the purpose of a test of differences?
To determine if groups differ significantly on a particular variable e.g mean scores, behaviours, attitudes
When do you use an independent samples t-test?
when comparing between two independent groups e.g. control vs experimental
What is the null hypothesis for an independent samples t-test?
The means of both groups are equal
What does the pooled estimate of the standard error assume?
That the variances of both groups are equal
When do you use a paired samples t-test?
When comparing two related samples
What is the null hypothesis for a paired samples t-test?
That the mean difference before and after is zero
When do you use ANOVA?
When testing differences in means across three or more independent groups
What is the null hypothesis for ANOVA?
All group means are equal
What does the F-Ratio in ANOVA represent?
The ratio of variance between groups to variance within groups
What does a large F-Ratio suggest in ANOVA?
A significant difference between group means
What test checks if group variances are equal before running a t-test or ANOVA?
Levenes test
What are non-parametric test used for?
When data doesn’t meet the assumptions of a parametric test e.g. non-normal distribution, unequal variances
What’s the difference between statistical and practical significance?
Statistical shows the difference is unlikely due to chance an dpractical considers if the difference atually matter in the real world
