Explain the components of a research design. b. Briefly explain the different types of research designs.

Explain the components of a research design. b. Briefly explain the different types of research designs.

The components of research design-

•    Dependent and Independent variables:

A magnitude that varies is known as a variable. When changes in one variable depends upon the changes in one or more other variables, it is known as a dependent or endogenous variable, and the variables that cause the changes in the dependent variable are known as the independent or explanatory or exogenous variables.

For example, if demand depends upon price, then demand is a dependent variable, while price is the independent variable.

•    Extraneous variable:

The independent variables which are not directly related to the purpose of the study but affect the dependent variable are known as extraneous variables. For instance, assume that a researcher wants to test the hypothesis that there is relationship between children’s school performance and their self-concepts, in which case the latter is an independent variable and the former, the dependent variable. In this context, intelligence may also influence the school performance. However, since it is not directly related to the purpose of the study undertaken by the researcher, it would be known as an extraneous variable.

•    Control:

One of the most important features of a good research design is to minimize the effect of extraneous variable.

•    Confounded relationship:

The relationship between dependent and independent variables is said to be confounded by an extraneous variable, when the dependent variable is not free from its effects.

There are a number of research designs. 

They are -

1. Experimental, historical and inferential designs (American Marketing Association).
2. Exploratory, descriptive and causal designs (Selltiz, Jahoda, Deutsch  and Cook).
3. Experimental and expost fact (Kerlinger)
4. Historical method, and case and clinical studies (Goode and Scates)
5. Sample surveys, field studies, experiments in field settings, and laboratory experiments (Festinger and Katz)
6. Exploratory, descriptive and experimental studies (Body and Westfall)
7. Exploratory, descriptive and casual (Green and Tull)
8. Experimental, „quasi-experimental designs‟ (Nachmias and Nachmias)
9. True experimental, quasi-experimental and non-experimental designs (Smith).
10. Experimental, pre-experimental, quasi-experimental designs and Survey Research (Kidder and Judd).

In fact, there are different perspectives from which any given study can be viewed. They are:

1. The degree of formulation of the problem (the study may be exploratory or formalized)
2. The topical scope-breadth and depth-of the study(a case or a statistical study)
3. The research environment: field setting or laboratory (survey, laboratory experiment)
4. The time dimension (one-time or longitudinal)
5. The mode of data collection (observational or survey)
6. The manipulation of the variables under study (experimental or expost facto)
7. The nature of the relationship among variables (descriptive or causal)