1. Correlation Coefficient
Chapter 13
Correlation Coefficient
We are now moving from comparing groups on one variable to comparing relationships between two (ore more) variables (left side of path-chart).
When to use: When you want to know the likelihood of a relationship or association between two variables. Is there a significant relationship between two variables? (Not causal!!!!!)
Here, the relationship between variables and NOT the difference between groups are being examined.
Steps:
1. State Null and Research Hypothesis

2. Null Hypothesis
Ho: Ρxy = 0
Research Hypothesis
H1: rxy ≠ 0
2. Set risk level (.05, of course)
3. Appropriate test statistic (flow chart) = t
Compute test statistic (by hand or computer)
Analyze, correlate, bivariate
Move two variables to correlated over, click okay

3. Determine obtained value
If by hand, determine df and one or two-tailed (again, one if you have a strong expectation and two otherwise). Here, n is the number of pairs or cases. You subtract by 2 (# of variables rather than groups) with correlation analysis (n-2). Find critical value (SPSS, again, computes significance automatically). (if by hand, Table B4 in Appendix B).
6. Compare and Evaluate Null