Post by neurology admin on Feb 21, 2013 5:08:44 GMT -5
Using SPSS for t Tests
This tutorial will show you how to use SPSS version 12.0 to perform one-sample t-tests, independent samples t-tests, and paired samples t-tests.
This tutorial assumes that you have: Downloaded the standard class data set (click on the link and save the data file) Started SPSS (click on Start | Programs | SPSS for Windows | SPSS 12.0 for Windows) One Sample t-Tests
One sample t-tests can be used to determine if the mean of a sample is different from a particular value. In this example, we will determine if the mean number of older siblings that the PSY 216 students have is greater than 1.
We will follow our customary steps:
Write the null and alternative hypotheses first: H0: µ216 Students ≤ 1 H1: µ216 Students > 1 Where µ is the mean number of older siblings that the PSY 216 students have. Determine if this is a one-tailed or a two-tailed test. Because the hypothesis involves the phrase "greater than", this must be a one tailed test. Specify the α level: α = .05 Determine the appropriate statistical test. The variable of interest, older, is on a ratio scale, so a z-score test or a t-test might be appropriate. Because the population standard deviation is not known, the z-test would be inappropriate. We will use the t-test instead. Calculate the t value, or let SPSS do it for you!