Statistical Methods for Psychology

Cognitive Task

NS: 27 34 19 20 56 35 23 37 4 30 4 42 34 19 49

DS: 48 29 34 6 18 63 9 54 28 71 60 54 51 25 49

AS: 34 65 55 33 42 54 21 44 61 38 75 61 51 32 47

Driving Simulation

NS: 15 2 2 14 5 0 16 14 9 17 15 9 3 15 13

DS: 70601217111443516511

AS: 320062064100623

I will omit hand calculations here on the assumption that you can carry them out your-

self, and in fact it would be good practice to do so. In Exhibit 13.1 you will find the analy-

sis of these data using SPSS.

Section 13.5 Analysis of Variance Applied to the Effects of Smoking 427

SmokCond

Nonsmoking Delayed Active

Estimated Marginal Means

50

40

30

20

10

0

Driving Simulation

Cognitive

Pattern Recognition

TASK

Estimated Marginal Means of DV

(a) Summary table

Tests of Between-Subjects Effects

Dependent Variable: DV

Source Type III Sum of Squares df Mean Square F Sig.

Corrected Model 31744.726a 8 3968.091 36.798 .000
Intercept 45009.074 1 45009.074 417.389 .000
Task 28661.526 2 14330.763 132.895 .000
SmokCond 354.548 2 177.274 1.644 .197
Task * SmokCond 2728.652 4 682.163 6.326 .000
Error 13587.200 126 107.835
Total 90341.000 135
Corrected Total 45331.926 134

aR Squared 5 .700 (Adjusted R Squared 5 .681)

(b) Interaction plot

Exhibit 13.1 Analysis of Spilich et al. data