Solomon Four t-Test

The Solomon Four t-Test applet is an experimental design to study treatment effects. The Solomon four-group design is a research design that attempts to take into account the influence of pretesting on subsequent posttest results. Participants are randomly divided into four groups and each group experiences a different combination of experimental manipulations: the first group (A) receives the pretest, the treatment, and the posttest; the second group (B) receives only the treatment and posttest; the third group (C) receives the pretest, no treatment, and a posttest; and the fourth group (D) receives only a posttest. The major advantages of the Solomon four-group design over a traditional two-group pretest–posttest design are that it reduces the influence of confounds and that it can pinpoint whether changes in the dependent variable are due to some interaction effect between the pretest and the treatment.

Solomon Four t-Test allows you to:

1. Design the experiment

2. Enter data

3. Conduct the analysis

4. Make inferences

5. Print a report