Calcite | Level 5

## Replicate results from SPSS for repeated-measures ANOVA with one factor - Angry Birds vs. Tetris

I want to replicate the results of Task 4  (Page 24) in the following document:

https://edge.sagepub.com/system/files/chapter15_1.pdf

Here is the problem's statement.

Angry Birds is a video game in which you fire birds at pigs. Some daft people think this
sort of thing makes people more violent. A (fabricated) study was set up in which people
played Angry Birds and a control game (Tetris) over a two-year period (one year per
game). They were put in a pen of pigs for a day before the study, and after 1 month, 6
months and 12 months. Their violent acts towards the pigs were counted. The data are in
the file Angry Pigs.sav. Does playing Angry Birds make people more violent to pigs
compared to a control game?

I have attached the data set.  This problem involves a repeated-measures ANOVA with one binary factor.

I have 5 questions:

1) Can I get Figure 18 (Page 25) automatically from a statistical procedure, or do I have to use PROC SGPLOT to do it manually?

2) Is there a statistical procedure that provides Outputs 16 and 17 (Page 26)?

3) I ran the following code:

data v1;
retain id;
set h2;

if VideoGame = 'ExperimentalGroup-AngryBirdsVideoGame'
then VideoGame = 'ab';
else if VideoGame = 'ControlGroup-TerisVideoGame'
then VideoGame = 'tetris';

ID = _n_;

rename VideoGame = game
ViolentAct_Baseline = baseline
ViolentAct_Time1 = t1
ViolentAct_Time2 = t2
ViolentAct_Time3 = t3;

run;

proc glm
data = v1;
class game;
model baseline t1 t2 t3 = game / nouni;
means game / welch;
repeated time 4 / printe;
title 'Repeated-measures ANOVA';
title2 'Within-subjects factor: time';
title3 'Between-subjects factor: game';
quit;
title;

I got this output.

Why is it different from Output 18 on Page 26?  How can I replicate Output 18?

4) How do I replicate the Levene's test of equality of error variances (Output 19, Page 27)?

5) How do I replicate the contrasts in Output 22 on Page 28?

3 REPLIES 3
Super User

## Re: Replicate results from SPSS for repeated-measures ANOVA with one factor - Angry Birds vs. Tetris

My first question would be were you able to replicate the results using SPSS?

While that may sound facetious there is method to that question. The  document only shows, at least from a quick scan, the point and click interface approach to getting tasks done. My experience with SPSS was that every release changed the menus and sometimes quite significantly. Significant => completely rewrite steps for described processes, such as this paper, because things had been removed sometimes including the basic menu item.

Providing the SPSS code generated might help as that changes a bit slower than the point and click menus.

Calcite | Level 5

## Re: Replicate results from SPSS for repeated-measures ANOVA with one factor - Angry Birds vs. Tetris

Hi ballardw,

You ask a very good question.  I don't have SPSS, so the best that I can do is look at this document and try to replicate the results in SAS.

Super User

## Re: Replicate results from SPSS for repeated-measures ANOVA with one factor - Angry Birds vs. Tetris

If you are in a University or similar environment perhaps you can find someone taking classes that use SPSS and can go through the menus and generate the code. After creating the data set of course.

My SPSS is very rusty but someone may be able to help with SPSS to SAS code.

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