Transcript File - Munro AP Psychology

Psychological Research
Methods
Excavating Human Behaviors
Why do we need science?
Science is usually the best thing we
have. Without science, we’d still be
drilling holes in people’s heads to get
the demons out. We’d hold on to our
beliefs even if they were wrong.
What is Experimental
Research?
• Explores cause and effect relationships.
• Has control and experimental groups
• Laboratory experiments are good at controlling variables.
Eating too many bananas causes
Constipation
Experimental Vocabulary
• Independent Variable: factor that is manipulated (the
medicine) (What you are doing to the subject)
• Dependent Variable: factor that is measured (anxiety)
• Extraneous or Confounding Variables: factors that
affect DV, that are not IV. (factors that screw up the
experiment!) (other meds?, other sources of stress)
• Experimental Group: Group exposed to IV (those who
get the pill)
• Control Group: Group not exposed to IV (Those who
get the sugar pill)
• Placebo: inert substance that is in place of IV in Control
Group (The sugar pill)
Steps in Designing an
Experiment
1.
2.
3.
4.
5.
6.
7.
8.
9.
Hypothesis
Pick Population: Random Selection then Random
Assignment.
Operationalize the Variables
Identify Independent and Dependent Variables.
Look for Extraneous Variables
Type of Experiment: Blind, Double Blind etc..
Gather Data
Analyze Results
repeat
Let’s do an experiment.
• Hypothesis: The red pill will reduce
anxiety.
• We operationalize the definition of anxiety
to mean those whose doctors claim they
suffer from anxiety.
• We find 100 people who fit the
operationalized definition
• We randomly assign half the men to the
experimental group and half the men to the
control group. (Same with women).
• I, the researcher, do not know which group
will receive the medication and which will
receive the placebo. That means this is a
double-blind experiment. This will reduce
experimenter bias.
• The experimental group will receive the actual
medication. The medication is called the
independent variable.
• The control group will receive a sugar pill (the
placebo).
• The research team will ask all participants to
measure their level of anxiety on a scale from 1 to
10. Anxiety is the dependent variable (what is
measured).
• The control group will usually report a
decrease in anxiety even though they
received no medicine. This is called the
placebo effect.
• Now that the experiment phase is done, you
must consider the confounding variables.
This is the stuff that will screw up your
experiment. Ex: what if the control group
had a mean age much less than the
experimental group? What if the 2 groups
had a different percentage of women?
• Our original hypothesis was: the red pill
will reduce anxiety by 40%.
• Results: The experimental group reported a
mean of 10% reduction in anxiety versus a
5% reduction for the control group.
• Theory: After several replications, the
medicine has no significant effect on
anxiety.
Reliability and validity?
• A finding is reliable if it can be replicated.
If subsequent studies show that the red pill
reduces anxiety then the findings are
reliable, thus supporting the hypothesis.
• A study is valid if it measures what it is
supposed to measure. If our experiment
measured hypertension instead of anxiety,
then the test in invalid, even if it is reliable.
Is the FSA valid and reliable?
• If a similar FSA test given to a group of 7th
graders produces the same scores, then it’s
reliable.
• If students fail the 7th grade math FSA
because the wording is on the 10th grade
level, then people might question the
validity. A valid math test tests math, not
reading level. Hmmmmm.
Non-experimental types of
research.
What is going on in this picture?
We cannot say exactly, but we
can describe what we see.
Thus we have…..
Descriptive Research
• Any research that observes and records.
• Does not talk about relationships, it just
describes.
Types of Descriptive Research
• The Case Study
• The Survey
• Naturalistic Observation
• Cross-sectional study
The Case Study
• Where one person (or situation) is
observed in depth.
What are the strengths and weaknesses of using
a tragedy like the Columbine School Shootings as
a case study?
Longitudinal studies
• A subject is studied for a long long long
time.
• Twins separated at birth are surveyed at
ages 5, 10, 15, 20, 30 years.
Cross-sectional study
• Different groups of people are compared
and contrasted.
• Blacks vs whites on attitudes towards
psychotherapy
• Poor vs. middle-class on extrovertedness
The Survey Method
• Used in both descriptional and
correlational research.
• Use Interview, mail, phone, internet
etc…
• The Good- cheap, anonymous, diverse
population, and easy to get random
sampling (a sampling that represents
your population you want to study).
Random Sampling
sample
census
Why do we sample?
• One reason is the False Consensus
Effect: the tendency to overestimate
the extent to which others share our
beliefs and behaviors.
Survey Method: The Bad
• Low Response
Rate
• People Lie or
just misinterpret
themselves.
• Wording Effects
• Social
desirability bias.
How accurate would a survey be
about the frequency of
diarrhea? Homosexuality?
Infidelity?
Naturalistic Observation
• Observing and
recording
behavior in
natural
environment.
• No control- just
an observer.
What are the benefits and detriments of
Naturalistic Observation?
Correlational Research
• Detects how well one variable predicts, not causes
another variable.
• Does NOT say that one variable causes another.
There is a positive
correlation between
ice cream and murder
rates. Does that mean
that ice cream causes
murder?
Correlation
• Studies show that there is a strong
correlation between how many books are
present in a child’s home and college
completion rate.
• Do the books cause a person to complete
college?
Correlation and Causation
• Three possible cause-effect relations
Low
Self-esteem
Depression
Low
Self-esteem
Depression
Low
Self-esteem
Depression
Distressing events or
biological predisposition
Measured using a correlation
coefficient.
• A statistical measure of the extent
to which two factors relate to one
another
What is a Correlation Coefficient
Which correlation coefficient has the
strongest relationship? The
weakest?
•
•
•
•
•
A. .79
B. -.88
C. .09
D. 3.6
E. -.05
B has the strongest. E has the weakest D. is invalid
Analyze Results
• Use measures of central tendency
(mean, median and mode).
• Use measures of variation (range and
standard deviation).
What is bias?
• Attitudes and beliefs that can skew results.
Hindsight Bias
• The tendency
to believe,
after learning
the outcome,
that you knew
it all along.
Many believe that Obama was better
for the country. Would we feel
different if McCain won?
Experimenter bias
• The people running the experiment think they
know the truth already.
• Ex: The tobacco industry funds an experiment.
The results: cigarette smoke has a neutral effect on
asthma.
• Ex: A doctor wants to cure AIDS, so she
unconsciously biases the experiment by giving the
sickest patients the placebo.
2 types of statistics
• Descriptive statistics are used to reveal
patterns through the analysis of numeric
data (describe what is there) (Ex: 25% of
Republicans pray before sex.)
• Inferential statistics make an inference
about the population from a sample. Ex:
predicting how people will vote based on
polling a 1000 people.
What is an institutional review
board?
• All academic research must be approved by
an institutional review board at a local
university. They review it for ethics and
procedural errors.
Ethical guidelines for animal
research?
• 1. must have clear scientific purpose
• 2. humane care for animals
• 3. animals must be trapped or bought
legally
• 4. suffering must be minimized.
Guidelines for human research?
• Coercion – Participation must be voluntary
• Informed consent – They must know that they are
involved in research and give their consent. If
they are deceived, what they DID consent to must
be similar to actual study. Minimize trauma.
• Anonymity/confidentiality/privacy
• Risk – mental and physical safety
• Debriefing procedure – afterward,
participants must be told of purpose of
study - need ability to contact researcher
about results.
What is the IV? DV?
• A researcher was interested in the effects of
reward on intrinsic motivation. Some children
were told that they would be given a special award
for drawing with magic markers (an activity they
already enjoyed). Other children were simply
asked to draw with the magic markers. One week
later, the children were unobtrusively observed for
how much time they spent drawing with the
markers. The children who expected and received
a reward for drawing with the markers were less
likely to draw with them later.
• In an investigation of the fundamental attribution error,
subjects were given a speech to read that either favored or
opposed Fidel Castro, the communist leader of Cuba.
Subjects were told that the speech was written by a student
who had been assigned to the position taken in the paper
(that is, the student writing the speech had no choice on
which position to take). Nevertheless, subjects believed
that the student who wrote the pro-Castro speech had
positive attitudes toward Castro, while subjects who read
the anti-Castro paper believed the writer had negative
attitudes toward Castro.
• Within a classroom setting, subjects were asked to listen to
a guest instructor. All subjects were given a description of
the instructor. Some subjects read a description containing
the phrase “People who know him consider him to be a
rather cold person...”, while other people read a description
where the word “warm” was substituted for the word cold
(otherwise, the descriptions were identical). After the
lecture, subjects were asked to rate the instructor. Subjects
who were told the instructor was warm gave him more
favorable ratings compared to subjects who were told that
the instructor was cold.
• Subjects watched a videotape of a woman
taking an SAT-like test. In all cases, she
correctly answered 15 out of 30 questions.
But subjects who observed a pattern of
initial success followed by failure perceived
the woman as more intelligent than did
those who observed the opposite pattern of
failure followed by success.
• Subjects read about a woman who used a
particular title, and then rated her on a
number of traits. When the woman used the
title Ms. rather than Miss or Mrs., she was
assumed to be more assertive, achievement
oriented, and dynamic, but also cold,
unpopular, and unlikely to have a happy
marriage
• People were randomly approached on the street by
a stranger and were asked to use his camera to take
a picture of him for a school project. For half of
the subjects, the camera didn’t work--the stranger
looked concerned, said that the camera was rather
delicate, asked the subject if he touched any of the
dials, and announced that it would have to be
fixed. For the other half of the subjects, the
camera worked fine. Further down the street, a
woman dropped a file folder of papers. Forty
percent of the subjects who had the working
camera experience helped the woman pick up her
papers, while 80% of the subjects who were led to
believe that they broke the woman’s camera
helped.
Chapter 1 Quiz
The Research Enterprise in
Psychology
Don’t forget to write your answers on a
separate piece of paper to grade when you’re
done!
1. Organized sets of concepts that explain
phenomena are
a) independent variables
b) dependent variables
c) hypotheses
d) theories
2. “Students will be able to read a statement
printed in the Comic Sans font faster than
the same statement written in the Lucida
Calligraphy font.”
The previous statement is a(n)
a) hypothesis
b) theory
c) replication
d) operational definition
3. A theory is
a) a tentative statement about the
relationship between two or more variables
b) a system of interrelated ideas used to
explain a
set of observations
c) a statement of research results that have
been
proven to be correct
d) a preliminary proposal that has yet to be
tested
4. Theoretically, random assignment should
eliminate
a) sampling error
b) the need to use statistics
c) concerns over validity
d) many confounding variables
5. When subjects in the experimental group put a
puzzle piece in the wrong place, the experimenter
unconsciously winced. The experimenter did not
wince when subjects in the control group put a
piece in the wrong place.
The wincing of the experimenter must be
eliminated because it is
a) fraudulent
b) a demand characteristic
c) a confabulation
d) a confounding variable
6. The two basic types of statistics are
a) descriptive and inferential
b) central tendency and variability
c) sampling and correlative
d) parametric and nonparametric
7. Of the following, which research method is
most effective for studying unusually
complex or rare phenomena?
a) controlled experiment
b) surveys
c) naturalistic observation
d) case study
8. Of the following, which research method
would be most appropriate for investigating
the relationship between political party
membership and attitude toward the death
penalty?
a) controlled experiment
b) naturalistic observation
c) test
d) survey
9. Of the following, the strongest positive
correlation would most likely be shown
between
a) an adult’s weight and running speed
b) close friendships and happiness
c) sense of humor and years of education
d) visual acuity and salary
10. John wants to study the effects of alcohol on the
behavior of college students. For his study, he
spends 5 hours every night for 2 weeks at a bar
near a college watching how the patrons act
before and after drinking alcoholic beverages.
The research method John is employing is a
a) controlled experiment
b) survey
c) test
d) naturalistic observation
11. What is the median of the following
distribution: 6, 2, 9, 4, 7, 3?
a)
b)
c)
d)
4
5
5.5
6
12. Of the following, the correlation
coefficient that indicates the strongest
relationship between the two variables
being measured is
a) +0.65
b) -0.89
c) 0.00
d) +3.45
13. Inferential statistics help us determine
whether ________ played a role in an
experiment
a) chance
b) a dependent variable
c) a normal distribution
d) genetics
14. Placebo effects occur when
a) the sample is not representative of the
population
b) two variables are confounded
c) subjects are influenced by the social
desirability bias
d) due to their expectations, subjects
experience some change from a
nonexistent or ineffective treatment
15. Which set of concepts is NOT a closely
related set?
a) mean, median, mode
b) method, results, discussion
c) experiment, independent variable,
control group
d) correlation, sample, journal
Chapter 2 Answer Key
1. D
2. A
3. B
4. D
5. D
6. A
7. D
8. D
9. B
10. D
11.
12.
13.
14.
15.
B
B
A
D
D
Essay Question Possibilities!!
• One of the following essay questions will
appear on your test, be familiar with all of
them!!
Essay Question # 1
• Design a simple experiment to investigate
the effects of television violence on
children’s aggressive behavior, being sure
to identify the independent and dependent
variables, and the experimental and control
groups.
Essay Question # 2
• Design a simple descriptive/correlational
study to investigate the relationship between
television violence and children’s
aggressive behavior.