Statistical Methods for Psychology

Section 16.9 The Factorial Analysis of Covariance 617

Type III

Sum of

Squares

36389.602b

892.395

4644.876

23870.485

563.257

1626.511

8942.324

90341.000

45331.926

Source

Corrected Model

Intercept

DISTRACT

TASK

SMKGRP

TASK * SMKGRP

Error

Total

Corrected Total

df

9 1 1 2 2 4

125

135

134

Mean

Square

4043.289

892.395

4644.876

11935.243

281.629

406.628

71.539

F

56.519

12.474

64.928

166.836

3.937

5.684

Sig.

.000

.001

.000

.000

.022

.000

Eta

Squared

.803

.091

.342

.727

.059

.154

Noncent.

Parameter

508.671

12.474

64.928

333.673

7.873

22.736

Observed

Powera

1.000

.939

1.000

1.000

.699

.977

Tests of Between-Subjects Effects

Dependent Variable: ERRORS

aComputed using alpha 5 .05

bR Squared 5 .803 (Adjusted R Squared 5 .789)

1. Task * Smoking Group
   Dependent Variable: ERRORS

Task

Patrecog

Cognitive

Driving

Smoking Group

NonSmokers

Delayed smokers

Active Smokers

NonSmokers

Delayed smokers

Active Smokers

NonSmokers

Delayed smokers

Active Smokers

Mean

9.805a

9.732a

9.558a

27.770a

40.436a

43.785a

8.505a

8.921a

5.820a

Std. Error

2.184

2.184

2.184

2.188

2.185

2.233

2.191

2.200

2.226

Lower

Bound

5.482

5.410

5.235

23.440

36.112

39.366

4.169

4.568

1.414

Upper

Bound

14.128

14.054

13.882

32.101

44.760

48.204

12.842

13.275

10.226

95% Confidence Interval

aEvaluated at covariates appeared in the model: DISTRACT 5 112.52.

2. Task
   Dependent Variable: ERRORS

Task

Patrecog

Cognitive

Driving

Mean

9.699a

37.330a

7.749a

Std. Error

1.261

1.274

1.273

Lower

Bound

7.203

34.810

5.230

Upper

Bound

12.194

39.851

10.268

95% Confidence

Interval

aEvaluated at covariates appeared in the model:

DISTRACT 5 112.52.

Exhibit 16.5 SPSS analysis of covariance of Spilich data

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