PSYC 212 Lecture Notes - Lecture 11: Null Hypothesis, Dependent And Independent Variables

• School: Towson University
• Department: Psychology
• Course: PSYC 212
• Professor: Kukucka

Document Summary

In a one-sample t-test, we compared a sample mean (taken from one sample of individuals) against a hypothesized population mean: ho(cid:449)e(cid:448)er, (cid:449)e ofte(cid:374) do(cid:374)"t ha(cid:448)e a(cid:374)(cid:455) i(cid:374)fo a(cid:271)out the populatio(cid:374) An independent-samples t-test is also called a between-subjects t-test: we are making a comparison between the people in group a and the people in. Any time we have one categorical independent variable, with two levels (i. e. , groups), and one continuous dependent variable. Independent t-test: the scary math part t = m1 m2 / ((df1 x sd1: + (df2 x sd2. This is how we estimate standard error for an independent t-test. It"s (cid:373)ore complicated because each group has some error in it. It does(cid:374)"t (cid:373)atter (cid:449)hi(cid:272)h group is (cid:862)group (cid:1005)(cid:863) a(cid:374)d (cid:449)hi(cid:272)h is (cid:862)group (cid:1006)(cid:863) A sample of 15 towson students has a mean sat score of 1220 (sd = 50) A sample of 18 loyola students has a mean sat score of 1170 (sd = 60)