It is always a good idea to describe your sample. Depending on the nature of the sample, the description may include the average age, education, classification of critical dimensions (grade in school, diagnosis, social class, sex, etc.), and other features that may be relevant to how the sample might respond on the task (IQ score, income, occupations).
If more than one group is being compared, you should describe each group separately and test to see if those groups differ on any of these demographic variables. For each of the demographic variable that describe the sample, click on the type of data it produces to select the appropriate descriptive and inferential statistics.