Unrelated t-test SPSS step by step PDF

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Unrelated t - test step my step for SPSS...

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Unrelated t-test: SPSS step by step

1. Open the data from Moodle Assessment: Study 4; “Study 4 Data SPSS”

2. Un-related t-test: Perceived Dangerousness Study  To analyse the perceived dangerousness study data we are going to run an unrelated t-test, because this is a between participants design  Two groups – social and biological cause  We will produce a bar chart to show the differences between the means of the two groups  Then we will carry out a t-test to see if this difference is significant.

3. Click on variable view 

The first thing we need to do is provide values for both “Condition” and “Sex”

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Click on the little blue box under values

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Then for both Condition and Sex add the following values: o Condition: Social = 1; Biological = 2 o Sex: Female = 1, Male = 2

o You do this by putting the value into the value box (e.g. 1) the label into the Label box (e.g. Social) then click add, repeat the process for the other condition then click OK. o It’s the same process for Sex.

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Now click on Data View By clicking on the A-1 tab on the top right hand of the toolbar you can check whether your labels have been added correctly

4. We’re now ready to create a Bar Chart 

Click on Graphs, Legacy Dialogs, then Bar

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Select Simple, Summaries of Groups of Cases and click Define

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Click on ‘Other statistic (e.g. , mean)’; move Dangerousness into the ‘Variable’ box and ‘Condition’ into the ‘Category axis’ box. Click on OK

Your Bar Chart should look like this:

5. Running the unrelated t-test  Click on Analyze, Compare Means, Independent Samples T Test

Move “Dangerousness” into the ‘test variable’ box and “Condition” into the grouping variable box.

Click on ‘Define Groups’. Enter ‘1’ for Group 1 and ‘2’ for Group 2, then Continue, then OK

6. Understanding the output The first table has the mean and standard deviation for the two conditions.

The second table gives you the t test results.

First, you have to check whether the variances are similar. This is the result of Levene’s test for Equality of Variances. If Levene’s is significant (below 0.05), this means the two conditions have different levels of variance. Here the Levene’s result is not significant.

This means we read the top line of the t-test results.

Results of the t-test.

This is the information we are interested in Find the… t- value: Degrees of freedom: p value (significance): Write out the results of the t-test following APA style guidelines (see lecture 15):...