This document discusses quasi-experimental research design. Quasi-experimental research involves manipulating an independent variable to observe its effects, but unlike true experiments, it lacks random assignment or a control group. The two main types discussed are non-randomized control group design, where groups are not randomly assigned but a control receives no treatment, and time series design, where a treatment is applied and removed over multiple time periods to a small group. Quasi-experimental designs are more practical than true experiments when randomization is not possible but allow evaluation of treatment effects under natural conditions.

1. QUASI
EXPERIMENTAL
RESEARCH DESIGN
Mr. Vipin Patidar
Asst. Prof.
K J Institute of Nursing, Vadasma

2. INTRODUCTION
• Quasi experimental research design involves the
manipulation of independent variable to observe
the effect on dependent variable.
• The study unlike true experimental study lacks at
least one of the three cardinal characteristic
(Randomization, Control)

3. • Quasi experimental designs have an element of
manipulation.
• Quasi experimental designs are generally used to
establish the causality (effect of independent variable
on dependent variable) in situations where
researchers are not able to randomly assign the
subjects to groups for various reasons.

4. CHARACTERISTICS
• Manipulation of the independent variable
to observe the effects of the dependent
variables.
• It lacks at least one of the two other essential
characteristics of the true experiment.

5. • Quasi independent variables are used instead
of true independent variables and
independent variable is not manipulated in
complete controlled situations.

6. TYPES
There are several types. The two important types are
as follows:
1. NON RANDOMIZED CONTROL GROUP DESIGN.
2. TIME SERIES DESIGN

7. NON RANDOMIZED CONTROL
DESIGN
• Is also known as “non equivalent control group
design”.
• This design is identical to the pre test- post test group
design, except there is no random assignment of the
study subjects in experimental and control groups.

8. • In this design experimental and control groups are
selected without randomization.
• Dependent variables are observed in experimental as
well as control groups before the intervention.

9. • Later the experimental group receives treatment,
following which the post test observation of
dependent variable is carried out for both the groups
to assess the effect of the intervention or treatment
on experimental group.

10. NON RANDOMIZED CONTROL
GROUP DESIGN
CONTROL
GROUP PRE TEST
TREATMENTEXP GROUP PRE TEST POST TEST
POST TEST

11. TIME SERIES DESIGN
• Time series design is useful when the researcher
intends to measure the effects of a treatment over a
long period of time.
• The researcher would to continue to administer the
treatment and measure the effects a number of times
during the course of the experiment.

12. • In a single - subject research, in which the
researcher carries out an experiment on an
individual or on a small number of
individuals, ……..by alternating between
administering and then withdrawing the
treatment to determine the effectiveness of
the intervention.

13. TIME SERIES DESIGN
EXP GROUP O2O1 O2 O3 O1 O3TREATMENT

14. EXAMPLE
• Measurement of a learner’s performance in a
college on weekly basis and then introducing a
new teaching technique. Then again
measuring on weekly basis.

15. ADVANTAGES
• Quasi experimental designs are more frequently
used because they are more practical and feasible
to conduct research.
• Where the sample size is small, and where
randomization & availability of control group is not
possible, this design is preferred.

16. • Quasi experimental design is more suitable for real
natural world setting than true experimental designs.
• This design allows the researchers to evaluate the
impact of quasi independent variables under
naturally occurring conditions.
• In some cases hypotheses are practically
answered through this design.

17. DISADVANTAGES
• In this design there is no control over
extraneous variables influencing the
dependent variable.
• The absence of a control group and absence of control
over the research setting makes the result of this design
less reliable and weak for the establishment of causal
relationship between independent & dependent
variable.

18. THANK YOU