Health Sciences 3801A/B Lecture Notes - Lecture 4: 2Degrees, Square Root, Histogram

• School: Western University
• Department: Health Sciences
• Course: Health Sciences 3801A/B
• Professor: Andrew Johnson

Document Summary

Stats lecture 4 notes independent groups t-test. The independent groups t-test: equation, assumptions of the independent groups t-test: Independent random samples: between groups and within groups, difficult to test, homogeneity of variance, normality. Homogeneity of variance: can"t really test for equality , this would be akin to confirming the null , better term is homogeneity , f = s2 large / s2 small. If you fail to reject, you have evidence that the variances are homogeneous. The f-ratio: f-ratios, are always positive, require 2 degrees of freedom (numerator and denominator, the f-max test, always greater than 1, numerator df = n large 1. Stats lecture 4 notes independent groups t-test: denominator df = n small 1. Pooling variance: when population variances are equal, however, we can pool the variances, equation: Effect sizes: equation, confidence interval surrounding mean equation, confidence interval surrounding mean difference equation: