Research Design
Experimental Methods
Standardization
Psychological Testing

Need for Psychological Research?
Are intuition and common sense enough to bring
forth answers about human nature?
 Are they free of error?
Examples:
 “Opposites attract”
Need for Psychological Research?

Limits of intuition:
• Personal interviewers tend to be overconfident of their “gut feelings”
about job applicants.
• Overconfidence:



We tend to think we know more than we actually do.
How long do you think would it take to unscramble the anagrams?
Anagram
• GRABE----------BARGE
• ETYRN----------ENTRY
• WREAT---------WATER



People said about 10 seconds.
On average they took about 3 minutes.
Errors in common sense:
• If you were to fold a piece of paper (0.1 mm thick) a 100 fold, how
large do you think its thickness would be?
• Answer:

800 Trillion times the distance between the sun and the earth.
Need for Psychological Research?

The Amazing Randi
• 1 million dollar check to anyone that can
(under conditions agreed upon by both parties)
prove the existence of any form of paranormal
activity.
Need for Psychological Research?



Psychology is a unique blend of biology, philosophy,
anthropology, linguistics, and sociology.
This makes psychology an important science because it
merges all the “gray areas” of other scientific fields into one
science.
Psychology gives us a place to answer philosophical
questions with hard, scientific methods.
Schools of Thought
Abnormal
Biological
Cognitive
Comparative
Counseling
Clinical
Critical
Developmental
Educational
Evolutionary
Forensic
Global
Health
Legal
Occupational Health
Personality
Quantitative
Social
School
Industrial/Organizational
Schools of Thought
Normality
Experimental Psychology
Research in psychology has five basic goals:

Describe

Explain

Predict


Control
Improve
Why did the subject produce the behavior?
The best predictor of future behavior is past behavior.
What can we do to change the behavior?
Experimental Psychology
Two Main Types of Psychological Research:
Basic: Study of psychological issues in order
seek knowledge for its own sake.
Applied: Study of psychological issues that
have direct practical significance
and application.
Theory

Explains how a number of separate facts are related.
•
•
•
•



An idea about a relationship.
Testable model capable of predicting future occurrences or observations.
Capable of being tested through experiment or verified through empirical
observation.
Experimental analysis is necessary in order to validate or invalidate a theory.
Empirical:
• Can be physically tested.
• Is understood through experience.
• Uses tools to weight and measure its boundaries.
Experiment:
• Manipulate a situation in order to prove/disprove a hypothesis.
Meta-Analysis:
• Summary of past research on a given topic.
Placebo


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Placebo:
• No treatment given
• Participant assumes treatment is present.
Confederate:
• Experimenter assumes the role of a participant or
antagonist.
Hawthorne Effect:
• Subjects improve an aspect of their behavior being experimentally
measured simply in response to being studied.
Animal Model

Necessary for research:
• Rats have similar immune system as humans.
• Mice have similar metabolism as humans.
• Monkeys have similar cognition processes as humans.
Research Process
“Too many cookies make penguins go crazy.”
1.
2.
3.
Have a question or idea about a relationship.
Develop a Null Hypothesis: (H0)
 The reverse of what the experimenter believes will happen.
 Cookies don’t make penguins go crazy.

Very easy to test this, all you have to do is find one
case where this is not so.
Develop an Alternative Hypothesis: (H1)
• Statement that attempts to describe or explain a given behavior.
 Leads to specific predictions of what will happen in very specific
situations.
 Certain types and quantities of cookies may make specific penguins
go crazy.
Research Process
4. Conduct the Experiment:
• Variable: Anything that can be measured or is changed.
 Independent Variable: Input variable.
 Dependent Variable: Outcome variable.
• Control Condition: No manipulation added.
• Operational Definition: How the phenomenon is to be observed and measured.
• Principal of Falsifiability: Hypotheses could be disproved if contradictory evidence were observed/introduced.
5. Complete the Result Section:
 Collected data from experiment, prove or disprove the null
• Statistical Significance: Results are probably true, not due to chance.
• Occam’s Razor: When conflicting results/solutions to a given problem occur, the shortest and least complex one
is the correct choice.
Potential Contamination of Results


Selection Bias: Occurs when differences between groups
are present at the beginning of the experiment.
• Solution:
 Random Assignment- Assigning the subjects to
each group based on chance rather than human
decision.
Placebo Effect: Involves the influencing of performance
due to the subject's belief about the results.
• Solution:
 Blind Study- Subjects are not informed of the
purpose of the experiment. Subjects are basically
blind to the expected results.
Potential Contamination of Results


Experimenter Bias: Changes in the results caused by the
experimenter. Experimenter behaves in a manner that
influences the participant.
• Solution:
 Double-Blind Study- Both the experimenter and
the subjects are blind to the purpose and anticipated
results of the study.
Volunteer Bias: If they care enough to be there then their
opinions/results may differ from ones that remain silent.
• Solution:
 None
Standardization
After an experiment is complete and the results obtained are
successful the next step is to standardize the experiment:
• All subjects must be given the same instructions
• All subjects must be presented with the instructions in the
same manner
• All data must be collected in exactly the same way
• Experiment needs to be replicated with different subjects
• Experiment must be reliable and valid:


Reliable: Test/Experiment produces the same results from one
time and place to the next.
Valid: Test/Experiment measures what it is suppose to measure.
Basically a test is considered to be standardized when it is
said to have:

“Stood the test of time”
Types of Research

Naturalistic Observation: Observing behavior in its
natural environment. Can involve counting specific
behaviors.
• Advantage: Provides more qualitative information
than the other methods.
• Disadvantage: Presence of an observer modifies the
participant’s behavior. No two observers produce the
same results.

Case Study: Following a single case for an extended period
of time.
• Advantage: Gather extensive information, both
qualitative and quantitative and can be helpful in
better understanding rare cases.
• Disadvantage: Only one case is involved severely
limiting generalization.
Types of Research

Survey: Questionnaires gather info from asking people
directly.
• Advantage: Can gather large amounts of information in
a relatively short time, cost effective.
• Disadvantage: Based solely on subjects’ responses
which can be inaccurate due to outright lying,
misunderstanding of the question, placebo effect,
and even the manner in which the question is asked.
Types of Research

Correlational Study: Determine if a relationship exists,
what direction the relationship is, and how strong it is.
• Positive Correlation: As one increases the other
increases, as one decreases the other decreases.
• Negative Correlation: As one increases the other
decreases, as one decreases the other increases.
• Advantage: Measures the strength of a relationship
between two groups.
• Disadvantage: Can’t make any assumptions of cause
and effect. No knowledge of effect of a third variable.
Positive:
Negative:
Positive Correlation
Negative Correlation
Psychological Testing
Measure personality traits, emotional states,
aptitudes, interests, abilities, and values.
• Usually measured as a single score.

Objective Tests:
• Participants is aware
• Feelings, attitudes, beliefs
• Asking questions directly

Projective Tests:
• Participants are unaware
• Unconscious feelings
• Examples: Rorschach Test, Draw a Person, Play
Therapy, Draw-A-Person, Sentence Completion
Psychological Testing
Psychological testing
categories:



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Achievement and aptitude
Intelligence
Neuropsychological
Occupational
Personality
Specific Clinical
Justification for using
tests:



It is easier to get
information from tests
than by clinical interview.
The information from tests
is more scientifically
consistent than the
information from a clinical
interview.
It is harder to get away
with lying on a test than
an interview.