Irfan Ahmed, PhD

Many analyses in psychological research involve testing hypotheses about means or mean differences. Below we describe the SPSS procedures that allow you to determine if a given mean is equal to either a fixed value or some other mean. One-sample t-test You perform a one-sample t-test when you want to determine if the mean value of a target variable is different from a hypothesized value. To perform a one-sample t-test in SPSS • Choose Analyze then goto Compare Means then goto One-sample t-test . • Move the variable of interest to the Test variable(s) box. • Change the test value to the hypothesized value. • Click the OK button. The output from this analysis will contain the following sections. • One-Sample Statistics . Provides the sample size, mean, standard deviation, and standard error of the mean for the target variable. • One-Sample Test . Provides the results of a t-test comparing the mean of the target variable to the hypothesized value. A significant test statistic indi