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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 e conomy in procedure.
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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 differentquantitative 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
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.