This document outlines the objectives and contents of a presentation on experimental designs. It aims to review experimental designs, study their importance, understand related terminology, and explain different types of designs. The presentation covers the introduction to and importance of experimental designs. It defines basic terminology and discusses types of designs like before-after, randomized block, Latin square, and factorial designs. The conclusion reiterates that experiments allow establishing cause-and-effect relationships but validity issues can arise, so designs aim to control confounding factors.

1. 1
““A REVIEW ON EXPERIMENTAL DESIGNS”A REVIEW ON EXPERIMENTAL DESIGNS”
PRESENTING BY,PRESENTING BY,
Ms. SONALI B. DIWATEMs. SONALI B. DIWATE
GUIDED BY,GUIDED BY,
PROF. N. KULKARNIPROF. N. KULKARNI
MODERN C.O.P.,MOSHI, PUNE-412105MODERN C.O.P.,MOSHI, PUNE-412105
08/07/14

2. To Review and Study theTo Review and Study the Experimental DesignsExperimental Designs
OBJECTIVEOBJECTIVE
1. To collect the information about Experimental Designs.1. To collect the information about Experimental Designs.
(Literature Survey)(Literature Survey)
2.To study the importance of Experimental Designs.2.To study the importance of Experimental Designs.
3.To understand the basic terminologies related to Experimental Designs3.To understand the basic terminologies related to Experimental Designs
4. To explain the types of Experimental Designs.4. To explain the types of Experimental Designs.
5. Summarization of the information.5. Summarization of the information.
208/07/14

3. CONTENTS…..CONTENTS…..
1. AIM AND OBJECTIVE1. AIM AND OBJECTIVE
2.INTRODUCTION TO EXPERIMENTAL DESIGNS2.INTRODUCTION TO EXPERIMENTAL DESIGNS
3. IMPORTANCE OF EXPERIMENTAL DESIGNS3. IMPORTANCE OF EXPERIMENTAL DESIGNS
4.BASIC TERMINOLOGIES RELATED TO EXPERIMENTAL DESIGNS4.BASIC TERMINOLOGIES RELATED TO EXPERIMENTAL DESIGNS
5. TYPES OF EXPERIMENTAL DESIGNS5. TYPES OF EXPERIMENTAL DESIGNS
6. SUMMERY6. SUMMERY
7. CONCLUSION7. CONCLUSION
8. BIBLIOGRAPHY8. BIBLIOGRAPHY
308/07/14

4. INTRODUCTION TO EXPERIMENTAL DESIGNSINTRODUCTION TO EXPERIMENTAL DESIGNS[]
 An EXPERIMENTAL DESIGN consists of a description of how a particular
hypothesis can be experimentally tested.
 The strategy that directs the researcher in planning & implementing the
study in way that is most likely to achieve the intended goal.
IMPORTANCE OF EXPERIMENTAL DESIGNS
• It helps in bioavailability & bioequivalence studies.
• It helps in determining the plasma drug level in different formulations.
• It is used to ensure the clinical performance of different products.
• It is important when researcher want to study the effects of two or more
independent variables at the same time.
• It represent the complexity which occurs during real experiment accurately.
• It gives idea about variations due to time effect. 4
08/07/14

5. What do these studies tell you?
• Experimental research allows the researcher to control the
situations.
• Permits the researcher to identify cause and effect relationships
between variables and to distinguish placebo effects from
treatment effects.
• Experimental research designs support the ability to limit
alternative explanations and to infer direct causal relationships in
the study.
• Approach provides the highest level of evidence for single studies.
508/07/14

6. What these studies don't tell you?
• The design is artificial, and results may not generalize well to
the real world.
• The artificial settings of experiments may alter subject
behaviors or responses.
• Experimental designs can be costly if special equipment or
facilities are needed.
• Some research problems cannot be studied using an
experiment because of ethical or technical reasons.
• Difficult to apply ethnographic and other qualitative methods
to experimental designed research studies. 608/07/14

7. 08/07/14
BASIC TERMINOLOGIESBASIC TERMINOLOGIES

8. 8
 Before & after without Control Design
 After Only with Control Design
 Before & After with Control Design
 Completely Randomized Design
 Randomized Block Design
 Latin Square Cross Over Design
 Factorial Design
TYPES OF EXPERIMENTAL DESIGNSTYPES OF EXPERIMENTAL DESIGNS
08/07/14

9. BEFORE & AFTER WITH CONTROL DESIGN
9
• In this designs two areas are selected & the dependent variable is
measured in both for identical time period before the treatment.
• The treatment is then introduced into the test area only & the dependent
variable is measured in both for identical time period after the
introduction of the treatment.
• The treatment effect is determined by subtracting the change in
dependent variable in control area from the change in dependent variable
in test area.
TIME PERIOD I TIME PERIOD II
TEST AREA LEVEL OF PHENOMENON
BEFORE TREATMENT (X)
TREAT.INTRODUCED
LEVEL OF PHENOMENON
AFTER TREATMENT (Y)
CONTROL AREA LEVEL OF PHENOMENON
WITHOUT TREATMENT (A)
Treat effect=(Y-X)-(Z-A) LEVEL OF PHENOMENON
WITHOUT TREATMENT (Z)
08/07/14

10. AFTER ONLY WITH CONTROL DESIGN
10
• One of the forms of experimental design used in marketing research.
• Here the researcher manipulates the independent variable and then it is
followed by a post measurement.
• Two groups are post measured, that is, control and experimental groups.
• The difference between the groups is mainly attributed to be the affect of
independent variable.
• This design escapes the problems of pretesting, history and maturation.
However, this form of "after-only design" does not facilitate an analysis of
the process of change.
08/07/14

11. COMPLETELY RANDOMIZED DESIGN
11
• In a completely randomized design, objects or subjects are
assigned to groups completely at random.
• One standard method for assigning subjects to treatment
groups is to label each subject, then use a table of random
numbers to select from the labeled subjects.
• This may also be accomplished using a computer.
• One of the most widely used experimental designs.
• The design is especially suited for field experiments where
the number of treatments is not large.
• The primary feature is the presence of blocks of equal size,
each of which contains all treatments.08/07/14

12. ADVANTAGES:
1. The design is extremely easy to construct.
2. The design is easy to analyze even though the sample sizes might not be
the same for each treatment.
3. The design can be used for any number of treatments.
DISADVANTAGES:
1. Although the completely randomized design can be used for any number
of treatments, it is best suited for situations in which there are relatively
few treatments.
2. The experimental units to which treatments are applied must be as
homogeneous as possible. Any extraneous sources of variability will
tend to inflate the error term, making it more difficult to detect
differences among the treatment means.
1208/07/14

13. RANDOMIZED BLOCK DESIGN
13
• If an experimenter is aware of specific differences among groups of
subjects or objects within an experimental group, he or she may prefer
a randomized block design to a completely randomized design.
• In a block design, experimental subjects are first divided into
homogeneous blocks before they are randomly assigned to a treatment
group.
• If, for instance, an experimenter had reason to believe that age might be a
significant factor in the effect of a given medication, he might choose to
first divide the experimental subjects into age groups, such as under 30
years old, 30-60 years old, and over 60 years old.
• Then, within each age level, individuals would be assigned to treatment
groups using a completely randomized design.
• In a block design, both control and randomization are considered.
08/07/14

14. ADVANTAGES:
1. The design is useful for comparing t treatment means in the presence of
a single extraneous source of variability.
2. The statistical analysis is simple.
3. The design is easy to construct.
4. It can be used to accommodate any number of treatments in any
number of blocks.
DISADVANTAGES:
1. Because the experimental units within a block must be homogeneous,
the design is best suited for a relatively small number of treatments.
2. This design controls for only one extraneous source of variability (due to
blocks). Additional extraneous sources of variability tend to increase the
error term, making it more difficult to detect treatment differences.
3. The effect of each treatment on the response must be approximately the
same from block to block.
1408/07/14

15. LATIN SQUARE CROSS OVER DESIGN
15
• Latin square design contains t rows and t columns.
• The t treatments are randomly assigned to experimental units within the
rows and columns so that each treatment appears in every row and in
every column.
• Each formulation is administered just once to each subject & once in each
study period.
• Unlike parallel designs, all the subjects do not receive the same
formulation at the same time, in a given study period , they are
administered different formulations.
08/07/14

16. ADVANTAGES:
1. The design is particularly appropriate for comparing t treatment means
in the presence of two sources of extraneous variation.
2. The analysis is quite simple.
DISADVANTAGES:
1. Although a Latin square can be constructed for any value of t, it is best
suited for comparing t treatments.
2. Any additional extraneous sources of variability tend to inflate the error
term, making it more difficult to detect differences among the treatment
means.
3. The effect of each treatment on the response must be approximately the
same across rows and columns.
1608/07/14

17. FACTORIAL DESIGN
17
• In an experiment, independent variable is often called as factor, especially
in experiments that includes two or more independent variable.
• A research that includes two or more factors is called as factorial design.
• This kind of design is often referred to by the no. of its factors as a two
factor designs or three factor design.
• A research study with only one independent variable is often called as
single factor design.
• Each factor is denoted by letter (A,B,C).
• Factorial designs are the notation system that identifies both the no of
factors & the no of values or levels that exist for each factor.
TYPES OF FACTORIAL DESIGNS : 1.Simple Factorial Design
2.Complex Factorial Design08/07/14

18. CONCLUSIONCONCLUSION
• Experimentation offers the possibility of establishing a cause and effective
relationship between variables and this makes it an attractive methodology to
researchers.
• Experiments are of two types: those conducted in a laboratory setting and
those which are executed in natural settings; these are referred to as field
experiments.
• Laboratory experiments give the researcher direct control over most of the
variables that could affect the outcome of the experiment.
• There are a number of potential impediments to obtaining valid results from
experiments.
• These may be categorized according to whether a given factor has internal
validity, external validity, or both.
• Internal validity is called into question when there is doubt that the
experimental treatment is actually responsible for changes in the value of the
dependent variable.
1808/07/14

19. BIBLIOGRAPHYBIBLIOGRAPHY
19
08/07/14

20. Thank
You…..--------------------------------------------------------------------------------
Thank
You…..--------------------------------------------------------------------------------