A research design is a plan or blueprint that guides how research will be conducted, including what data will be collected and how it will be analyzed. It aims to address the research question in an efficient way. A good research design facilitates the research process, makes it more effective and efficient, and yields useful results with minimal time and costs. It helps control for unwanted variables and errors to obtain valid and objective conclusions about the relationship between variables. The key components of a research design include sampling, observations, statistics, and operational aspects.

2. “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.”
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. Just as for better.
Defining Research Designs

3. A research design is a basic plan that guides the data
collection and analysis phases of the research project. It
provides the framework that specifies the type of
information to be collected, its sources and collection
procedure (Kinnear & Taylor, 1996; Churchill & Iacobucci
2005) define research design: “it is the blueprint that is
followed to complete the study” and it “ensures that the study
is relevant to the problem and will use economical
procedure”.
Decisions regarding what, where,
when, how much, by what means
concerning an inquiry or a
research study constitute a
research design.

4. Research Designs
Different research designs can be conveniently categorized as:
• Research design in case of exploratory research studies;
• Research design in case of descriptive and diagnostic research
studies, and
• Research design in case of hypothesis-testing research studies.

5. One may split the overall research design into the following
parts :
• Sampling design
• Observational design
• Statistical design
• Operational design
Parts of a Research Design

6.  The sampling design which deals with the method of
selecting items to be observed for the given study;
 The observational design which relates to the conditions
under which the observations are to be made;
 The statistical design which concerns with the question of
how many items are to be observed and how the
information and data gathered are to be analysed; and
 The operational design which deals with the techniques by
which the procedures specified in the sampling, statistical
and observational designs can be carried out.

7. Research Designs can be distinguished
based on Exploratory and Diagnostic Study

9. The Selection of any research design is based upon the purpose of the
investigation, types of the variables and the condition in which the
research is to be conducted.
Research Design is the detailed plan of the investigation. It is the blueprint
of the detailed procedures of testing the hypothesis and analyzing the
obtained data.
So, it maybe defined as the the sequence of those steps taken ahead of
time to ensure that the relevant data will be collected in a way that
permits objective analysis of the different hypothesis formulated with
respect to the research problems.
Thus ,the research design helps the researcher in testing the hypothesis by
reaching valid and objective conclusions regarding the relationship
between independent & dependent variable.

10.  It is a plan that specifies the sources and types of information relevant
to the research problem.
 It is a strategy specifying which approach will be used for gathering
and analyzing the data.
 It also includes the time and cost budget since most studies are done
under these two constraints.
In brief, research design must , at-least, contain
a) A clear statement of the research problem.
b) Procedures and techniques to be used for gathering information.
c) The population to be studied.
d) Methods to be used in processing and analyzing data.

11. Research Design is needed because it facilitates the
smooth sailing of the various research operations
thereby, making research as effective & efficient as
possible, yielding maximal information with
minimal expenditure of effort ,time and money

12. The purpose of any research design is to provide a maximum amount of
information relevant to the problem under investigation at a minimum
cost.
Basically, a research design serves two functions :
First, it answers the research questions as objectively, validly and
economically as it is possible. This is an important function served by any
research design. The research problems are usually epitomized by the
hypothesis.
• It suggests to a researcher how to collect data for testing these
hypothesis , which variables should be treated as control variables.
• What methods of manipulation will be more adequate in a particular
context, what types of statistical analyses should be done and finally a
possible answer to the research problems.
• Thus a research design, after moving through the sequence of different
related steps ,enables the researcher to draw a valid and objective
answer to research problems.

13. Second, a researcher design also acts as a control mechanism. In other
words, it enables the researcher to control unwanted variances. In any
scientific investigation there are three types of common variances,
namely, the experimental variance, the extraneous variance and error
variance with which the researcher is directly concerned.
1.Experimental Variance
Experimental variance is produced in the dependent variable by the
manipulation of the experimental variables or the independent variables
by the experimenter.
Usually , the experimenter or the researcher wants to maximize the
experimental variances, so that he can get as valid and objective data as is
possible.
For maximizing the experimental variance, the investigator experiments
in a way that different experimental conditions become as different as
possible.

14. 2.Extraneous Variance or Control Variance
Extraneous variance or control variance is produced by the extraneous
variables or the relevant variables . An experimenter always tries to
control the relevant variables and thus , also wants to eliminate the
variances produced by these variables. For elimination of extraneous
variance it is essential that the extraneous variables be properly
controlled.

15. 3.Error variance
The third function of a research design is to minimize the error variance.
The error variance is defined as those variances or variability's in the
measure which occur as a function of the factors not controllable by the
experimenter.
Such factors may be related to the individual differences among the subjects
themselves , such as their attitudes , motivation , need , ability , etc., or they
may be related to what is commonly called the errors of measurement ,
such as the difference in trials , differences in conditions of experiment ,
temporary emotional state of the subject , fatigability , etc.

16. Whatever the source of error variance , it has three distinct features :
i) Error variance is self compensating because sometimes the variability
is positive and sometimes the variability is negative
ii) Since error variance is both positive and negative , it tends to cancel
out in several repeated measurements. Hence, it can be said that in
several repeated measurements the mean of the error variance will be
zero.
iii) Error variance is unpredictable probably because it is based on
random errors. In this way , the error variance is distinct from
systematic variance because the latter is predictable and based upon
systematic errors.

17. The minimization of error variance basically serves two purposes :
First, it improves the variability of measure so that the generalization can be
more dependable and accurate.
Thus, it strengthens the external validity of the experiment .
Second, it gives the systematic variance a chance to show its significance, if
it really is significant.
If the error variances ( in ANOVA usually the within the group variance ) is
large , the systematic variance ( or between variance ) will not be
significant.
The error variance can be usually minimized by controlling the conditions
of the experiment. If the different conditions of an experiment are fully
controlled , the occurrence of error variance is minimized to agreat extent.
In an experiment allowing many uncontrolled conditions , the error
variance accumulates to higher proportions.
Finally, it maybe added that one of the objectives of a good research is to
provide unambiguous results and to avoid “confounding”.