Test 2: independent samples t-test, Mann-Whitney, Paired samples t-test, & Wilcoxon

nonparametric test of differences between two means

mann-whitney is this type

Independent samples test

compares the means of two independent groups in order to determine whether there is statistical evidence that the associated population means are significantly different.

two sample t-test

systat path for an independent samples test

Kruskal-wallis

Another name for a mann-whitney test

NonParametric tests the differences between 2 means

Mann-whitney

parametric test of differences of two means of dependent data

Paired samples

Helpful to understanding

The independent-samples t-test (or independent t-test, for short) compares the means between two unrelated groups on the same continuous, dependent variable. For example, you could use an independent t-test to understand whether first year graduate salaries differed based on gender (i.e., your dependent variable would be "first year graduate salaries" and your independent variable would be "gender", which has two groups: "male" and "female"). Alternately, you could use an independent t-test to understand whether there is a difference in test anxiety based on educational level (i.e., your dependent variable would be "test anxiety" and your independent variable would be "educational level", which has two groups: "undergraduates" and "postgraduates").

Paired samples t-test

a procedure for testing whether the means of two metric variables are equal in some population. Both variables have been measured on the same cases. Although "paired samples" suggests that multiple samples are involved, there's really only one sample and two variables.

ranked, ordinal scales

for a mann-whitney test the data is transformed from original scale into _____ _____

Parametric tests the differences between 2 means

independent samples t-test

Mann-Whitney

tests whether two sample means are from the same population