Question

What differentiates experimental from non-experimental designs? Give an illustration of a situation in which an experimental design would be preferred and one in which a non-experimental design would be preferred

Answer 1

Experimental Design: It is a systematic and scientific approach to research in which the researcher manipulates one or more variables, and controls and measures any change in other variables. These designs are based on a clear hypothesis, the purpose of the research is to confirm or refute the validity of the hypothesis. Experimental research designs have an independent variable, a dependent variable, and a control group. Most of the experiments are conducted in a laboratory in a controlled environment. This is an experiment where the researcher manipulates one variable, and control/randomizes the rest of the variables. It has a control group, the subjects have been randomly assigned between the groups, and the researcher only tests one effect at a time. It is also important to know what variable(s) you want to test and measure.

Example of research design question might be 'What will be effect of adding certain chemical on the characteristics of the product?'

Non-experimental Design: Non-experimental research designs are carried out in natural settings, it does not involve manipulation of the situation, event, circumstances or people.

Survey, case studies, correlational studies comparative studies and descriptive studies are some of the examples of non-experimental research design. Longitudinal studies are also non-experimental research and the purpose of these studies is to study a situation, people or phenomenon over a period of time to observe the change.

Example of non-research design question is 'What motivates the customers buy my products?'