One of the other method used in research is Experimental Research.
Meaning and Characteristics
Experimental research is concerned with cause and effect relationship. To qualify as an experiment, a research design need only posses the following three properties:
1) Manipulation - The researcher manipulates some of the subjects.
2) Control - Researcher introduces one or more controls over the experimental situation, including the use of a control group.
3) Randomization - Researcher assigns subject to a control or experimental group on random basis.
Let us suppose you want to test the effects of information gained through an organized pre-natal health teaching programmes, e.g. "group approach. You also want to know whether your teaching would make the difference or something else which is not in your control. That means you want to study the possible cause and effect relationship by exposing one group (experimental group) to a "treatment" and then compare the results with the findings of another group (control group) which is not exposed to the "treatment". The "treatment" in this example is an organized pre-natal health teaching programme but it can also be drugs, conditions, procedure, nutrients, etc. One of the simplest true experimental designs is called the pretest-post-test control group design as shown in Fig.
pretests (Knowledge test) both groups (Represented by symbol 0,) exposes the experimental group to the teaching (symbol x) and then post tests (same as knowledge test in pre-test) both groups (represented by symbol 0,). All conditions except "teaching" should remain the same for both groups. The investigator can find the difference of the measures for both groups and compare the groups on the selected variable. Refer to Unit 1 where you have learnt about variables. Can you identify the independent variable and the dependent variable? The variable i.e. considered as the "cause" is "teaching "whereas the variable as "effect" is knowledge score" as measured by pre- or post-test is the dependent variable. The control group is necessary to make sure that it is the "treatment" or the "teaching" that has caused the knowledge increase and not something else, because if there is something else (such as radio or TV talk) then control group will also be exposed to this and you will not find the difference in knowledge between experimental and control groups. The very fact that there is a difference between these two groups, the investigator logically says that the "treatment" given has made the'difference.