Homework #34

The means below are from a hypothetical study of the role of drive level and drugs on the learning performance of monkeys. The animals are given a series of 20 "oddity" problems. In this task, three objects (two of the same, one different). Are presented to the monkeys, and the subjects task is to learn to select the non-duplicated or odd object. A food reward is placed in a food well underneath the correct object. A trial consists of the presentation of three objects and the monkey's selection of one of them. The response measure Y is the number of errors in 20 trials of training. One of the independent variables Factor A consists of a Control and two Drug conditions, and the other variable Factor B is the drive level of animals, either 1 hour of food deprivation of 24 hours of food deprivation. Four moneys are randomly assigned to each treatment combination. The mean number of errors for each condition are presented below along with the results of the analysis of variance.

SourceSSdfMSF²Cohen's F

Factor A(Drug)112.00256.003.06

Factor B (Motivation) 24.00124.001.31

A x B144.00272.003.93*

S/AB (error)330.001818.33

Write in the appropriate Omega Square and Cohen's F values above next to the associated factor. Also answer the following questions

1. Which number above is the average variance within each of the groups?

1. What number above is the variability of the main effect drug means around the grand mean ?

The interaction is significant. For the significant interaction, test the simple effect of Motivation (food deprivation-one hr vs. 24 hrs) at each level of drug using the Tukey and the Fischer's LSD and write out your conclusions separately for each test.

ControlDrug XDrug Y

One Hour3.0010.0014.00

24 Hour11.0012.0010.00

824

Tukey CD=

Results:

1.Main Effect of Hours of Training is significant

5 Hours10 Hours 15 Hours

Mean27.667 35.33342.00

27.6677.66614.333

35.3336.667

42.00

Tukey Test Critical Difference

(1)Turkey CD = (7.666) x SQRT (62.500/15) = 7.02

Conclusions from Tukey: 15 hours > 5 hours, 10 hours > 5 hours

LSD Test Critical Difference

(1) LSD =

Conclusions from LSD=

2.Interaction of Beat x Hours is significant

I choose to look at whether the simple effects of training change depending upon the type of beat that the officer patrols

Effect of Hours at Upper:

33.0035.0038.00

33.00--25

35.00---3

38.00--

Conclusions from Tukey=

LSD Test Critical Difference

(1) LSD =

Conclusions from LSD=

Effect of Hours at Middle:

30.0031.0036.00

30.00--16

31.00---5

36.00--

Conclusions from Tukey=

LSD Test Critical Difference

(1) LSD =

Conclusions from LSD=

Effect of Hours at Lower:

20.0040.0052.00

20.00--2032

41.00---12

51.00--

Conclusions from Tukey=

LSD Test Critical Difference

(1) LSD =

Conclusions from LSD=