Chapter 3

Chapter 3

1. Research Design

   • A research design is the arrangement of conditions for collection and analysis of data in a manner that aims to combine relevance to the research purpose with economy in procedure
     • As such the design includes an outline of what the researcher will do from writing the hypothesis and its operational implications to the final analysis of data. More explicitly, the desing decisions happen to be in respect of:
       • (i) What is the study about? (ii) Why is the study being made? (iii) Where will the study be carried out? (iv) What type of data is required? (v) Where can the required data be found? (vi) What periods of time will the study include? (vii) What will be the sample design? (viii) What techniques of data collection will be used? (ix) How will the data be analyzed? (x) In what style will the report be prepared?
   • Need for Reasearch Design
     • Research design is needed because it facilitates the smooth sailing of the various research operations, thereby making research as efficient as possible yielding maximal information with minimal expenditure of effort, time and money.
   • Features of a Good Design
     • A good design is often characterised by adjectives like flexible, appropriate, efficient, economical and so on. Generally, the design which minimises bias and maximises the reliability of the data collected and analysed is considered a good design
       • A research design appropriate for a particular research problem, usually involves the consideration of the following factors:
         • (i) the means of obtaining information; (ii) the availability and skills of the researcher and his staff, if any; (iii) the objective of the problem to be studied; (iv) the nature of the problem to be studied; and (v) the availability of time and money for the research work.
   • Important Concepts Relating to Research Design
     • 1. Dependent and independent variables: A concept which can take on different quantitative values is called a variable. As such the concepts like weight, height, income are all examples of variables.
       • 2. Extraneous variable: Independent variables that are not related to the purpose of the study, but may affect the dependent variable are termed as extraneous variables.
         • 3. Control: One important characteristic of a good research design is to minimise the influence or effect of extraneous variable(s).
           • 4. Confounded relationship: When the dependent variable is not free from the influence of extraneous variable(s), the relationship between the dependent and independent variables is said to be confounded by an extraneous variable(s).
             • 5. Research hypothesis: When a prediction or a hypothesised relationship is to be tested by scientific methods, it is termed as research hypothesis.
               • 6. 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.
                 • 7. Experimental and control groups: In an experimental hypothesis-testing research when a group is exposed to usual conditions, it is termed a ‘control group’, but when the group is exposed to some novel or special condition, it is termed an ‘experimental group’.
                   • 8. Treatments: The different conditions under which experimental and control groups are put are usually referred to as ‘treatments’.
                     • 9. Experiment: The process of examining the truth of a statistical hypothesis, relating to some research problem, is known as an experiment
                       • 10. Experimental unit(s): The pre-determined plots or the blocks, where different treatments are used, are known as experimental units. Such experimental units must be selected (defined) very carefully.
   • Different Research Desings
     • Different research designs can be conveniently described if we categorize them as: (1) research design in case of exploratory research studies; (2) research design in case of descriptive and diagnostic research studies, and (3) research design in case of hypothesis-testing research studies.
       • 1. Research design in case of exploratory research studies: Exploratory research studies are also termed as formulative research studies.
         • 2. Research design in case of descriptive and diagnostic research studies: Descriptive research studies are those studies which are concerned with describing the characteristics of a particular individual, or of a group, whereas diagnostic research studies determine the frequency with which something occurs or its association with something else
           • 3. Research design in case of hypothesis-testing research studies: Hypothesis-testing research studies (generally known as experimental studies) are those where the researcher tests the hypotheses of causal relationships between variables.
   • Basic Principles of Experimental Designs
     • Professor Fisher has enumerated three principles of experimental designs: (1) the Principle of Replication; (2) the Principle of Randomization; and the (3) Principle of Local Control.
       • According to the Principle of Replication, the experiment should be repeated more than once.
         • The Principle of Randomization provides protection, when we conduct an experiment, against the effect of extraneous factors by randomization.
           • The Principle of Local Control is another important principle of experimental designs.
   • Important Experimental Design
     • Experimental design refers to the framework or structure of an experiment and as such there are several experimental designs. We can classify experimental designs into two broad categories, viz., informal experimental designs and formal experimental designs
       • (a) Informal experimental designs: (i) Before-and-after without control design. (ii) After-only with control design. (iii) Before-and-after with control design.
       • b) Formal experimental designs: (i) Completely randomized design (C.R. Design). (ii) Randomized block design (R.B. Design). (iii) Latin square design (L.S. Design). (iv) Factorial designs.