This document provides an overview of different types of research designs, including descriptive research, developmental research, case study research, causal-comparative research, and true experimental research. Descriptive research involves collecting and presenting factual information to describe existing phenomena without explaining relationships. Developmental research assesses changes in development programs over time using longitudinal or cross-sectional studies. Case study research provides an intensive examination of a single unit or case. Causal-comparative research investigates possible causes for a situation by observing evidence and relationships between variables. True experimental research uses control groups and pre-/post-testing to measure the impact of interventions.

1. RESEARCH DESIGN

2. Meaning of Research Design
 Research design refers to a plan, structure and strategy of
investigation so as to obtain answer to research questions or
problems. In other words it is the detailed blueprint used to guide
 According to Sitelltiz et.al.(1962), “A research is the arrangement
of conditions for collection, measurement and analysis of data in a
manner that aims to combine relevance to the research purpose with
economy in procedure”.
 In fact, research design is a blueprint or detailed plan for how a
research study is to be completed. In other words it is a conceptual
structure within which the research is conducted.
 It seeks the answers to the questions like- what approach to the
problem should be taken? What methods will be used to tackle the
problem? What strategies will be most effective?

3. Types of research design
 There are various types of research design have been
suggested by different scholars. For instance, Selltiz et.al.
(1962) suggested three broad categories of research design
viz. (i) formulative or exploratory studies (ii) descriptive
studies and (iii) testing causal hypothesis studies.
 Here, we are following the research designs as given below:

4. Descriptive Research:
 It is essentially a fact finding study, generally conducted to
assess the behavior or characteristic of a given population or
to describe the overall situation or events occurring at present.
 In other words, it simply portrays the facts and does not
necessarily seek to explain relationship, test of hypothesis,
make predictions or implication of the study.
 The investigators collect the data, classify, tabulate, present
and analyze the data to describe about what exists, but they do
not fully analyze and explain why phenomena behave as they
do.
 For example, the studies like – descriptive study about the
workers in a factory, community welfare activity and
beneficiaries, state of physical health in rural area etc.

5.  Government or sometimes the development agencies
conduct the baseline survey of the particular district or
region of the country to know about the situation or
condition of the place in order to intervene some
development program is also a descriptive research.
 It is an accumulation of a database, that is solely descriptive.
 Researchers, however, are not in agreement on what
constitutes “descriptive research” and often broaden the term
to include all terms of research except historical and
experimental.
 Descriptive research contributes to any discipline primarily
by building a foundation of facts.

6.  The main purpose of the descriptive research may be
categorized as follows:
i. To collect detailed factual information that describes
the existing phenomena.
ii. To identify problems, current conditions and
practices.
iii. To make comparisons and evaluations.
iv. To determine what others are doing with similar
problems on situation and benefit from their
experience in making future plans and decisions.

7. Developmental Research:
 Development research is conducted for the purpose of assessing
the development work or program launched by the government
or any other agencies.
 It focuses to study the change in development work or program
and the related indicators, which affects the change and their
rate, direction and inter-related factors over a period of time.
 On the basis of rate of change, we can also predict for future
trend of the program.
 Developmental research may be conducted in the following two
ways:
(i) Longitudinal Study
(ii) Cross-sectional Study

8. Longitudinal Study:
 Longitudinal study is conducted to measure the change in
nature and rate of change of certain phenomena at different
stages of development.
 In this study, data are collected at two or more development
phases from the same group of individual in order to evaluate
the change of phenomena.
Cross-sectional Growth Study:
 Cross-sectional study is designed to cross check the result of
development phases. It measures the rate of changes by
drawing samples from a cross-section of the particular place
or society, where there has been intervened the development
activities.

9. Case study Research:
 The “case study” is very popular in research.
 It usually refers to a fairly intensive examination of a single unit.
A unit may be a person or a family or a small social group of
people or an institution or a community or a single company.
 In other words, it is essentially an intensive investigation of the
particular unit under consideration.
 The objective of this method is to locate the factors that account
for the behavior patterns of the given unit as an integrated
totality.
 According to H. Odum, “The case study method is a technique
by which individual factor whether it be an institution or just be
an episode in the life of an individual or a group is analyzed in
its relationship to any other in the group”.

10.  Case study method is a form of qualitative analysis where in
careful and complete observation of an individual or a
situation or an institution is done.
 But we must understand that a case study does not represent
the total reality. It is just an example of the social reality or
any other realities.
 Hence, a case study may be an intensive, integrated and
insightful method of studying the social phenomenon.
 It can be used to illustrate a theory by providing an example.
It enables us to explore, and understand the problems and
issues in relation to a particular situation.

11. Causal-comparative Research:
 This research investigates the possible causes affecting a
particular situation by observing the existing evidences and
searching for possible consequences (factors) leading to the
results.
 The main objective of this research is to study the situation or
problem in order to explain the relationship between two or more
variables.
 It is also known as ‘ex post facto’ research. In this method the
investigator takes one or more independent variables and
examines the results, seeking causes and consequences.
 It is basically conducted to find the clues about what might cause
or contribute to the particular phenomenon.
 This research predicts the dependent variable on the basis of
independent variables.

12. True Experimental Research
 There are so many types of experimental design. This
section, therefore is confined to describing those most
commonly used in social sciences:
Post-test only Control Group Design (After
only with Control):
 In some situations, when pre-test measurements were
not possible, but are to be investigated the possible
influence by exposing the dependent variable to
experimental intervention (or treatment) and comparing
the results with the control group, the post-test-only
control group or after only with control group design is
used.
 This design is diagrammed as follows:

13.  The effect of experimental treatment is measured by the
difference between O1 – O2 .
 Since the experimental group has been exposed to the
treatment, we might expect that the observed difference
(O1 - O2 ) might be due to the influence of experimental
treatment.
Experimental group
Control group
RA
X O1
O2
Time

14. Pre-test – Post-test Control Group Design (Before and After
with Control):
 A pre-test – post-test control group design or before – after
with control group design is the classic experimental
design.
 Thus there are two groups namely an experimental group
and a control group, which does not receive any treatment.
 Between time T1 (before) and T2 (after), the experimental
group is exposed to an experimental intervention
(treatment) and the control group is left alone.
 At both time T1 and T2, the experimental and control
groups are measured in relation to the key dependent
variable (or subject) that is of interest in the study.

15. BeforeT1 AfterT2
Experimental
Group
O1
O2
Control
Group
O3 O4
Intervention
Diff.=T1 –T2
Ediff. = O2 – O1
Cdiff. = O4 – O3
No Intervention
RA

16.  The measure of the subjects in the experimental group are
tested before and after being exposed to the treatment by O1
and O2 at times T1 and T2 respectively.
 The measures for the same in the control group on the same
subjects by O3 and O4.
 Since the experimental group has been exposed to the
treatment, we might expect that the difference in time
between T1 and T2 might be due to the influence of the
treatment, which is Ediff .
 However, it is to be noted that this observed difference
between T1 and T2 might also be due to factors other than
experimental intervention.
 A change could occur due to passing of time or might be due
to other set of possible factors.
 Hence to measure the real impact due to treatment, a control
or comparison group is needed. Ideally, this group should be
identical to the experimental group at time T1.

17.  However, the control group has not been exposed to any
experimental intervention. We can measure the change
on the subjects over time T1 and T2, which is denoted
by Cdiff.
 The crucial thing to look at is whether the experimental
group changed more than the control group.
 If it is changed significantly more, we normally would
conclude that this is because of the experimental
intervention.
 Of course, this conclusion is warranted only if both
groups were same to start with.
 In order to ensure that they are the same to start with,
people will be assigned randomly to the experimental
and control groups.

18. Quasi-Experimental Design:
 In many field of research situations, it is certainly very costly
or simply impossible and difficult to meet the random
assignment criteria of a true experimental design.
 Despite of some difficulties in conducting true experimental
studies due to its nature, researchers on the other hand want
to avoid the problems of validity associated with non-
experimental designs. In such case, it is reasonable to select
quasi-experimental design.
 These designs do not have the restrictions of random
assignment. At the same time, they do not adequately control
for problems of threats to internal validity.
 Followings are the types of quasi-experimental designs:

19. The after only design (one-shot case study):
 In an after only design, a population is being exposed to an
intervention and if the researcher wishes to study its impact on
the population, then this design (or one-shot case study) is
used.
 In this design, information on baseline (pre-test or before
observation) is usually constructed on the basis of
respondent’s recall of the situation before the intervention, or
from information available in existing records.
 The change in dependent variable is measured by the
difference between the ‘before’ (baseline) and ‘after’
observation.

20. X O
Treatment or intervention Observation or measurement
of dependent variable
 Technically this is not fair design for measuring the impact of
an intervention as there is no proper baseline data to compare
the ‘after’ observation with i.e. two sets of data are not
strictly comparable.

21. The before-and-after design (One group Pre-
test- Post test Design):
 The before-and-after design overcomes the problem of
retrospectively constructing the ‘before’ observation by
establishing it before the intervention is introduced to the study
population.
 When the program has been completely implemented, it is
assumed to have had its effect on the population, the ‘after’
observation is carried out to ascertain the impact attributable to
the intervention.
 The difference between O2 and O1 (O2 – O1) is the measure of
the influence of the experimental treatment.
 This design offers a comparison of the same group before and
after intervention.

22. O1
Before
(Pre-test)
X
Treatment or
intervention
O2
After
(Post-test)
The Time Series Design:
This design is similar to the non-experimental pre-test post-
test design except that there are repeated measurement
observations before and after the program intervention (X).
The advantage of this design is the multiple measurement
observations.

23.  For example, if we find that there is no difference between O1
and O2 and O3, but then a sudden increase occurs between O3
and O4 which is subsequently maintained in O5 and O6, we
can conclude with some degree of confidence that the sudden
increase was probably due to the effect of the program
intervention (X).
Experimental Group
Time
O1 O2 O3 X O4 O5 O6