It’s a type of true experimental design where test units are inconstantly allocated to an experimental group and a control group. Both groups are measured before and after the experimental group is exposed to a treatment. Here the main objective is to reduce threats
The Solomon four group design is mainly for avoiding the situations caused by Pretest – Posttest design. They have two additional control groups, minimizing the importance of the confounding variables, and letting the researcher know where the Pretest itself influences the subject
Factorial design is used to study the behavior of two or more independent variables, using a single dependent variable, whereas traditionally methods study about one variable, which is statistically easier to manipulate.
This is a type of experimental design known as independent measures, and while it might work, there are a few problems with using it in this experiment. Here the main problem is we have different groups resulting into various conclusion which is little tricky to pick up and there shows lot of variability in the results. In order to overcome this, we make measurements using only one group of subjects, where the tests on each subject are repeated like two or more times with different measures, where subject is exposed to all kind of treatments.
Experimental design where in a series of periodic measurements is taken from two test group units. The experimental group is exposed to a treatment and other series of periodic measurements is taken by both groups. It has a comparison group and more closely resembles a quasi- experimental design.