PSYCHOLOGICAL RESEARCH
DESIGN & METHODS
AP PSYCHOLOGY: CHAPTER 2
Bellwork: Why do we need
Psychological Research?
What were your thoughts..
Hindsight Bias
“I knew it all along”
phenomenon
Examples..
2 groups.. Absence
makes the heart
grow fonder or..
Weakens..
Flashcards..
Overconfidence
We tend to think we know more
than we do..
WREAT WATER
ETRYN ENTRY
GRABE BARGE
OCHSA
Overconfidence In history…
“We don’t like their sound. Groups of guitars are on their way out.” –
Decca Records in turning down a contract w the Beatles.
“They couldn’t hit an elephant at this distance.” General Sedgwick
just before being killed during a Civil War battle 1864;
Given random data, we look for order and meaningful patterns.
Order in Random Events
Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.
Order in Random Events
Given large numbers of random outcomes, a few are likely to express order.
Angelo and Maria Gallina won two California lottery
games on the same day.
Many people have been struck by
lightening 2+ times.
Think about it! An event
happens to 1 in a billion
people occurs 7 times a day, 2500 times a
year!
The Research Process (Big Picture)
The Research Process (The Detailed Picture)
Components of Research
Variables
• Factors or characteristics in research.
• Can be manipulated or measured.
Data
• # representing research findings
• Provide the basis for research conclusions.
Theory
• Statements that can account for, or predict behavior.
• Subject to critical thinking.
Components of Research
Critical Thinking
• Basis for research (stems from curiosity).
• Helps assess reliability & claims.
Hypothesis
• Testable prediction.
Operational Definition
• Descriptions of the EXACT operations or methods.
• Operational Definition Exercise
Research Methods
Goals
Describebehavior
Accurately predict
behavior
Demonstrate control over
Behavior
Explain how & why
behavior occurs.
Naturalistic Observation
Case Studies
Surveys
Correlational Studies
*Helps measure behavior
Experiments
*Helps determine cause & effect
Methods of Psychological Research (p. 44)
Method Features Strengths Weaknesses
Naturalistic
Observation
Observation of human or
animal behavior in the
environment it typically
occurs.
Provides descriptive data
about behavior presumably
uncontaminated by outside
influences.
Observer bias and
participant self-consciousness
can distort results.
Case Studies Intensive examination of the
behavior and mental
processes associated with a
specific person or situation.
Provide detailed descriptive
analysis of new, complex, or
rare phenomena.
May not provide
representative picture of
phenomena.
Surveys Standard sets of questions
asked of a large number of
participants.
Gather large amounts of
descriptive data relatively
quickly and inexpensively.
Sampling errors, poorly
phrased questions, and
response biases can distort
results.
Correlational
Studies
Examine relationships
between research
variables
Can test predictions,
evaluate theories, and
suggest new hypotheses.
Cannot confirm causal
relationships between
variables.
Methods of Psychological Research (p. 44)
Method Features Strengths Weaknesses
Experiment Manipulation of an
independent variable
and measurement of its
effects on a dependent
variable.
Can establish a cause-
effect relationship
between independent
and dependent variables.
Confounding variables
may prevent valid
conclusions.
Which Method to Use?
Identify parenting styles commonly used in the United States
Determine why a school failed to meet
appropriate standards.
Describe differences in gender communication
among 5 year old children.
Determine a relationship between
violent media (TV, video games, etc) and aggressive behavior.
Identify the capacity of human short term
memory.
Selecting Participants for Research
Random Sample
Participants selected from the population (whose members had an equal chance of being selected).
Attempts to avoid biased sampling.
Representative Sample
The sample of participants accurately reflect the greater population.
Attempt to represent as many characteristics as possible (age/gender, etc).
Population Sampling
Process of selecting participants who are members of the population.
Using the sample, researchers use generalizability to draw conclusions.
Selecting Participants for Research
Random
Sampling
Representative
Sample
Leads to…
Sampling Error
• Those selected may be slightly different than those not selected
Non Response Error
• Participants selected may not agree to participate.
Cost/Budget Issues
• Convenience Samples
• Drawing participants from conveniently available populations.
Population: Class of 1941
Random Selection of Subjects
Provides a Representative Sample of the Class of 1941
Experimental Group Control Group
Random
Assignment
of Subjects –
Makes
subjects in
both groups
equal:
controls for
subject
differences
Example:
•Can eye movements cause a change in emotion?
•Does Shapiro’s EMDR (eye movement desensitization and reprocessing) technique reduce anxiety?
•EMDR treatment causes a significant reduction in anxiety.
Experimental Method
Experimental Variables
Independent Variable
(IV)
Factor or condition being manipulated by experimenter.
EMDR
Dependent Variable
(DV)
Factor being measured.
Anxiety
Independent vs Dependent
1. Developmental psychologists want to know if exposing children to public television improves their reading skills.
2. Physiological psychologists wonder about the relationship between the intake of wine and emotional reactions to frightening stimuli.
3. Sensory psychologists want to know whether birds also experience visual illusions.
4. Operant psychologists want to know whether reinforcing (rewarding) comments will make people work harder on an assembly line.
5. Cognitive psychologists wonder what kind of diagrams are easiest for people to remember.
6. Comparative psychologist study whether a young monkey will prefer to spend time with a pretend monkey
7. made of wire that also provides milk or a pretend monkey that is covered with cloth but provides no milk.
8. A clinical psychologist wants to know whether people who have had psychotherapy are more or less likely to have problems in the future.
9. A social psychologist wants to know whether being polite or rude to people tends to make them more cooperative.
10. An organizational psychologist test to see if wearing name tags make the employees happier with their work.
11. A personality psychologist explores whether extroverted people have more fun at parties.
Experimental Subject Groups
Experimental Group
Exposed to the IV
Participants who receive
EMDR treatment
Control Group
Not exposed to the IV
Serves as a basis for
comparison
Participants who did not
receive EMDR treatment
ALL OTHER
CONDITIONS MUST
BE EQUAL! Why?
Confounding Variables
Factor that affects the DV (along with
or instead of the IV)
E Group: 50 min. focus on memory
C Group: 8 min.
Focus on memory
Experimental Controls
Control: Random Assignment
Random variables are evenly distributed.
Participants are distributed through a random process (computer
distribution, coin flip, etc).
Random Variables
Uncontrolled (or uncontrollable) that effect the DV.
Personality, background, life experiences, etc.
Experimental Controls
Experimenter Bias
Type of confounding variable
Unintentionally encourage participant responses to support hypothesis
Control: Double Blind Study (design in which experimenter nor participants
know who is a part of experimental or control groups
Participant Bias
Knowledge/expectation of treatment changes the participants
behavior/results.Control: Placebo Treatment
100 Depressed Subjects
50 - Drug
50 - No Drug
38 Improve
8 Improve
100 Depressed Subjects
50 - Drug
50 - Placebo
38 Improve
20 Improve
Placebo Effect