RESEARCH DESIGN
RESEARCH DESIGN Decisions regarding what, where, when, how much A research design 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.
The designing decisions happen to be in respect of: What is the study about? Why is the study being made? Where will the study be carried out? What type of data is required? Where can the required data be found? What periods of time will the study include? What will be the sample design? What techniques of data collection will be used? How will the data be analyzed? In what style will the report be prepared?
Research design refers to the blue print/road map for the collection, measurement & analysis of data
Split the overall research design into the following parts: (a) sampling design the method of selecting items to be observed; (b) observational design the conditions under which the observations are to be made; (c) statistical design how the information and data gathered are to be analyzed; (d) operational design the techniques
The important features of a research design (i) a plan specifies the sources & types of information relevant to the research problem (ii) a strategy which approach will be used for gathering and analyzing the data. (iii) the time and cost budgets most studies are done under these two constraints
Need for Research Design: It facilitates the smooth sailing of the various research operations Makes research as efficient as possible Yielding maximum information with minimal expenditure of effort, time and money Increases reliability of the results
Important Concepts relating to research: Variables: A concept which can take on different quantitative values Qualitative phenomena (or the attributes) are also quantified Eg: Weight, height and income…
Important concepts Cont’d Continuous variable Variable expressed using Decimal points Discrete (non-continuous) variable Variable Expressed using integer variables
Important concepts Cont’d Dependent variable Is a variable which depends upon or is a consequence of the other variable Independent variable Antecedent to the dependent variable Eg: compressive strength of concrete flexural strength of RC beam
Important concepts Cont’d Extraneous variable: Independent variables that are not related to the purpose of the study, but may affect the dependent variable Eg: Effect of w/c on fck Whatever effect is noticed on dependent variable as a result of extraneous variable(s) is technically described as an ‘experimental error’.
Important concepts Cont’d Control: design to minimize the influence or effect of extraneous variable(s). 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/confused by an extraneous variable(s).
Important concepts Cont’d Research Hypothesis: Predictive statement Relates the independent variable to a dependent variable Relationship that are assumed but not to be tested, are not termed research hypothesis
Important concepts Cont’d Experimental and non-experimental hypothesis-testing research: Experimental: a research where the independent variable is manipulated
Important concepts Cont’d Experimental and control group Control group: exposed to usual condition Experimental group: exposed some novel or special condition Eg:CJ
Important concepts Cont’d Treatment: The different conditions under which experimental and control groups are put Usual condition Special condition
DIFFERENT RESEARCH DESIGNS Research design in case of exploratory research studies Research design in case of descriptive and diagnostic research studies Research design in case of hypothesis testing
Basic principles of Experimental designs The principle of replication The principle of randomization The principle of local control
Repeated more than once To increase statistical accuracy Replication Repeated more than once To increase statistical accuracy
Randomization Provides protection against the effect of extraneous factors
Local control Extraneous factor is made to vary deliberately over as wide a range as necessary The variability it causes can be measured and hence eliminated from the experimental error Total variability…attributed(treatment + extraneous + experimental error)
Important Experimental Designs: Informal experimental design Formal Experimental design
Informal Experimental Design: Use less sophisticated form of analysis based on differences in magnitudes. Types: Before-and-after without control design. After-only with control design. Before-and-after with control design.
Formal Experimental Design: More control Uses precise statistical procedures for analysis Types: Completely randomized design (C.R. Design). Randomized block design (R.B. Design). Latin square design (L.S. Design). Factorial designs.