T for Two, as in Testing Two Groups or Two Times

Hey all, welcome to our Week 12 episode on t-tests! We've only got a few short weeks left of this course... and we're building upon last week by moving from inferential tests comparing a sample and a population to t-tests, which compare 2 sample groups or 1 sample group at 2 different times. For 2 totally separate groups with no overlap, we will be doing an independent samples t-test; for a single group that is being tested at 2 different times, we will be doing a dependent samples t-test (aka a paired-samples t-test). We'll discuss these tests are a brief review of our testing steps on critical values and how we know to reject the null hypothesis