This document discusses experimental research designs. It defines key concepts in experimentation including independent and dependent variables, experiments, and extraneous variables. It also covers validity in experimentation, addressing internal and external validity. Finally, it provides a classification of experimental designs, listing statistical designs such as completely randomized design, randomized block design, Latin square design, and factorial design.

1. Course: B.COm
Subject: Foundation of Research
Unit-2.1
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2. CHAPTER-4
EXPERIMENTAL RESEARCH DESIGNS
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3. What is an Experiment?
• An experiment is generally used to infer
a causality. In an experiment, a
researcher actively manipulates one or
more causal variables and measures
their effects on the dependent variable
of interest.
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4. Concepts Used in Experiments
• Independent variables: Independent variables
are also known as explanatory variables or
treatments. The levels of these variables are
manipulated (changed) by researchers to
measure their effect on the dependent
variable.
• Test units: Test units are those entities on
which treatments are applied.
• Dependent variables: These variables
measures the effect of treatments
(independent variable) on the test units.
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5. Concepts Used In Experiments
• Experiment: An experiment is executed when the
researcher manipulates one or more independent
variables and measures their effect on the
dependent variables while controlling the effect of
the extraneous variables.
• Extraneous variables: These are the variables other
than the independent variables which influence the
response of test units to treatments.
Examples: Store size, government policies,
temperature, food intake, geographical location, etc.
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6. Validity in Experimentation
• Internal validity: Internal validity tries to
examine whether the observed effect on a
dependent variable is actually caused by
the treatments (independent variables) in
question.
• External validity: External validity refers to
the generalization of the results of an
experiment.
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7. A Classification of Experimental
Designs
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8. Statistical designs
Statistical designs allow for statistical control and
analysis of external variables.
• Completely randomized design
• Randomized block design
• Latin square design
• Factorial design
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9. • Prepared By : Prof.Devrshi Upadhayay
• 9724256662
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