Important Concepts Relating To Research Design
Before described the different research design, it will be appropriate to explain the various concepts relating to design so that these may be better and easily understand.
- Dependent and independent variable: Concepts Relating To Research Design
A concept which can take on different quantitative values is called a variable. As such the concept like weight, income are all example of variables. Qualitative phenomena (or the attributes) are also quantified on the basis of the presence or absence of the concerning attribute(s). phenomena which can take on quantitatively different values even in decimal points are called ‘continuous variables’. But all variables are not continuous. If they can only be expressed in integer values, they are non-continuous variables or in statistical language ‘ discrete variable’. Age is an example of continuous variable, but the number of children is an example of non-continuous variables. If the one variable depends upon or is a consequence of the other variable is termed as an independent variable. For instance, if we say that height depends upon age, then height is a dependent variable.
- Extraneous variable: Independent variable that are not related to the purpose of the study, but may effect the dependent variable are termed as extraneous variables. Suppose the researcher wants to test the hypothesis that there is a relationship between children’s gains in social studies achievement and their self-concept. In this case self-concept is an independent variable and social studies achievement is a dependent variable. Intelligence may as well affect the social studies achievement, but since it is not relates to the purpose of the study undertaken by the research, it will be termed as an extraneous variable.
- Control: One important characteristic of a good research design is to minimize the influence or effect of extraneous variable(s). the technical term ‘control’ is used when we design the study minimizing the effect of extraneous independent variables. In experimental researches, the term ‘control’ is used to refer to restrain experimental conditions. (Concepts Relating To Research Design)
- Confounded Relationship: When the dependent variable is not free from the influence of extraneous variable’s, relationship between the dependent and independent variable is said to confounded by an extraneous variable’s.
- Research Hypothesis: (Concepts Relating To Research Design) When a prediction or a hypothesis relationship is to be tested by scientific method it is termed as research hypothesis. The research hypothesis is predictive statement that at least one independent variable to a dependent variable. Usually a research hypothesis must content objectively verified or the relationship that are assumed but not to be tested, are not termed research hypothesis.
- Experimental and non Experimental Hypothesis testing Research: When the purpose of research is to test a research hypothesis, it is termed as hypothesis-testing research. It can be of the experiment design. Research in which the independent variable is manipulated is termed ‘experimental hypothesis-testing research’ and research in which an independent variable is not manipulated is called ‘non-experimental hypothesis-testing research’.
- Experimental and control groups: In an experimental hypothesis research when a group is exposed to usual condition. It is termed an ‘experimental group’. In the above illustration, the Group A can be called a control group and the Group B an experimental group. If both group A and Bare exposed to special studies programs, then both groups would be termed ‘experimental groups’. It is possible experimental and control groups.