PSYC 412 Lecture Notes - Lecture 1: Statistical Inference, Null Hypothesis, Descriptive Statistics
Document Summary
They do not allow to say anything about people who were not included in the data set. Null hypothesis: there is no difference between these two groups. P-value: probability of obtaining a difference as big as the one observed when there actually is no different (typically . 05) When p < . 05, there is less than 5% chance that we would have obtained a difference that big if in reality no difference existed. Do children who have conduct problems have poorer language skills than do children without conduct problems. Relationship between two continuous variables: correlation (r) Null hypothesis: r = 0 (no correlation) Positive correlation: 0 < r < 1. Negative correlation: -1 < r < 0. Outcome/dependant variable (dv): number of years of school. Predictors/independent variables (iv): conduct disorder symptoms, family ses. Unique association of each iv with the dv ( ) Often we have more than one iv. Main effect: association between ivs and dv.
