# Scientific Methodology

```Scientific Methodology
Carolyn R. Fallahi, Ph. D.
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Why do research?
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What is the value of research?
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Types of Research
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Descriptive Methods
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Surveys
Naturalistic Observation – e.g. Jane Goodall
Clinical Method
Case Study, e.g. Freud
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Other Types of Studies
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Longitudinal, e.g. etiology of a psychiatric
disorder.
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National Institute of Mental Health
National Institute of Health
Cross Sectional, e.g. impact of driving with
age?
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Variables
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Independent Variable
Dependent Variable
Control Variables
IV, DV, CV
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Ethics
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The American Psychological Association
(APA)
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Protection from physical and mental harm.
Assurance that research is voluntary.
Informed consent.
Deception – limited.
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Correlation
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What is a correlational study?
What does correlation measure?
-1 through +1.
Zero
Example: drug study
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Hypotheses
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Null Hypothesis: Ho
Alternative Hypothesis: Ha
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Probability
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What is probability? Why do we use it in
research?
What is big enough?
What is the probability or the likelihood that
the null hypothesis will be rejected?
We get p-values by using statistics.
These formulas are different depending on
what type of study we are running.
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Probability
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For example: If we were studying
proportions, e.g. 7/100 patients improved with
drug 1 where 20/100 patients improved with a
placebo.
Z-test.
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Probability
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What if we had 4 different populations we
were interested in: men, women, old, young.
Chi Square.
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Probability
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Class Example: Drug Study to improve