BMS1042 Lecture Notes - Lecture 7: Null Hypothesis, Alternative Hypothesis, Relative Risk

• School: Monash University
• Department: Health Sciences - BMS
• Course: BMS1042
• Professor: Penny Robinson

Document Summary

Independent t-test: we are comparing the difference between the means of groups 1 and 2. Null hypothesis - there is no difference in the means of the two groups. Alternative hypothesis - there is a difference in the means of the two groups. Paired t-test: we are comparing the mean of the differences between groups 1 and 2. Null hypothesis - there is no difference between the mean of the compared individuals in the two groups. Alternative hypothesis - there is a difference between the mean of the differences between compared individuals in the two groups. If or = 1, there is no difference. If or < 1, there is a decreased risk (protective factor) If or > 1, there is an increased risk (risk factor) For example, if or = 1. 5, it means 50% increased risk. If the sample sizes are different, we divide the proportions by each other. Example: 20 people out of 200 smokers develop cancer.