1. SIMPLE AND MULTIPLE REGRESSION Chris Stiff [email_address]

7. LINE OF BEST FIT Amount of alcohol Stupid behaviour

8. LINE OF BEST FIT – POOR EXAMPLE Stupid behaviour Number of pairs of socks ?

11. SPSS OUTPUT

12. SPSS OUTPUT R = correlation between amount drunk and stupid behaviour R square = proportion of variance in outcome (behaviour) accounted for by the predictor (amount drunk) Adjusted R square = takes into account the sample size and the number of predictor variables

14. SPSS OUTPUT

15. SPSS OUTPUT Beta = standardised regression coefficient and shows the degree to which a unit increase in the predictor variable produces a standard deviation change in the outcome variable with all other things constant

22. MULTIPLE REGRESSION - EXAMPLE Attendance at lectures Books read Motivation Exam Performance (Grade) What might predict exam performance?

25. MULTIPLE REGRESSION: SPSS OUTPUT

26. MULTIPLE REGRESSION: SPSS OUTPUT

27. MULTIPLE REGRESSION: SPSS OUTPUT For overall model: F(2, 42) = 12.153, p<.001

28. MULTIPLE REGRESSION: SPSS OUTPUT Number of books read is significant predictor b=.33, t(42) = 2.24, p<.05 Lectures attended is a significant predictor b=.36, t(42) = 2.41, p<.05

32. ENTER OUTPUT

33. ENTER OUTPUT R square = proportion of variance in outcome accounted for by the predictor variables Adjusted R square = takes into account the sample size and the number of predictor variables

34. ENTER OUTPUT

35. ENTER OUTPUT Beta = standardised regression coefficient and shows the degree to which the predictor variable predicts the outcome variable with all other things constant

38. Don’t forget to choose the r-square change option from the Statistics menu

39. BLOCK ENTRY OUTPUT

40. BLOCK ENTRY OUTPUT NB – this will be in one long line in the output!

41. BLOCK ENTRY OUTPUT

42. BLOCK ENTRY OUTPUT