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PSYCHOLOGY
40S
RESEARCH METHODS
C. MCMURRAY
Source:
David Myers
PowerPoint Slides
Aneeq Ahmad
Henderson State University
Worth Publishers, © 2006
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The Need for Psychological Science
Intuition & Common Sense
Many people believe that intuition and common
sense are enough to bring forth answers regarding
human nature.
Intuition and common sense may help us with
our questions but they are not free of error.
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Errors of Common Sense
Try this !
Fold a piece of paper (0.1 mm thick) 100 times.
How thick will it be?
800,000,000,000,000 times the distance between
the sun and the earth.
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How Folding Paper Can Get You to the Moon
• Folding paper video
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Why is Research Important?
Source :Blair-Broeker/Ernst, Thinking About Psychology
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Goals of Psychology
The four basic goals of psychology are to:
1. Describe
2. Explain
3. Predict
4. Influence
To achieve these goals psychologists rely on various
methods of research to accomplish each of these goals.
(Descriptive research, correlational research and
experimental research)
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Hindsight Bias
Hindsight Bias is the “I-knew-it-all-along”
phenomenon.
Hindsight bias can make research findings seem like mere
common sense!
The goal of scientific research, however, is to predict what will
happen in advance.
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Overconfidence
Overconfidence is thinking that we
know more than we actually know.
How long do you think it
would take to unscramble
these anagrams?
People said it would take
about 10 seconds, yet on
average they took about 3
minutes (Goranson, 1978).
Anagram
WREAT
WATER
ETYRN
ENTRY
SREBA
BEARS
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Barnum Effect
“There’s a sucker born every minute!” (P.T. Barnum)
The Barnum Effect (sometimes
known as the Forer effect):
When people identify with and
easily accept information that is
favorable to them and/or what
they believe
P.T. Barnum
How Well Do You Know Yourself
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Barnum Effect
• How Well Do You Know Yourself
The Barnum Effect (sometimes known as the Forer effect):
When people identify with and easily accept information
that is favorable to them and/or what they believe
60 years ago a “Professor called Forer gave personality tests to his students,
ignored their answers, and gave each student an identical evaluation. The first three
items were:
• “You have a great need for other people to like and admire you”
• “You have a tendency to be critical of yourself”
• “You have a great deal of unused capacity which you have not turned to your
advantage”
• They were then asked to evaluate the description from 0 to 5, with 5 meaning the
recipient felt the description was an ‘excellent’ evaluation and 4 meaning the
assessment was ‘good.’ The class average evaluation was 4.26.”
Read more: (Source) https://www.psychologytoday.com/blog/sidewaysview/201411/weve-got-something-everyone-the-barnum-effect
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Critical Thinking
Critical thinking does
not accept arguments
and conclusions blindly.
It examines
assumptions, discerns
hidden values,
evaluates evidence and
assesses conclusions.
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Scientific Method
Psychologists, like all scientists, use the scientific method to
construct theories that organize, summarize and simplify
observations.
Five Basic Steps:
1. Formulate a specific question that can be tested
2. Design a study
3. Collect relevant data
4. Analyze the data to arrive at conclusions
5. Report the results
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Step 1: Formulate a specific question that can be tested
Does low self-esteem contribute to depression?
Your questions leads to a hypothesis.
A Hypothesis is a testable prediction or an educated guess
about the relationship between variables. (not a question)
Example: People with low self-esteem are apt to feel more
depressed.
Variable is a factor that can vary or change.
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Step 2: Design a study
Decide what type of research you will use
Research would require us to administer tests of selfesteem and depression. Individuals who score low on a
self-esteem test and high on a depression test would
confirm our hypothesis.
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Step 3: Collect relevant data
Collect the data from your research.
Research aims to gather data that either supports or
disproves a hypothesis.
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Step 4: Analyze the data to arrive at conclusions
Once observations have been made and measurements
have been collected, the data needs to be summarized and
analyzed. Researchers use the methods of a branch of
mathematics known as statistics.
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Step 5: Report the results
Researchers publish or share their finding with
other scientists. In addition to reporting their
results, psychologists provide a detailed
description of the study itself.
Describing the precise details of the study makes it
possible for other investigators to replicate or
repeat the study
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Research Process
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Research Methods
1. Descriptive Research
2. Correlational Research
3. Experimental Research
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Descriptive Research
Descriptive research observes and
describes behavior
Examples:
• Case Studies
• Surveys
• Naturalistic Observations
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Descriptive Research: Case Study
Case Study
A technique in which one person is studied in
depth to reveal underlying behavioral principles.
Advantages: provides insight into specific cases.
Susan Kuklin/ Photo Researchers
Is language uniquely human?
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Case Study
Clinical Study
http://behavioralhealth.typepad.com
A clinical study is a
form of case study in
which the therapist
investigates the
problems associated
with a client.
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Descriptive Research:
Naturalistic Observation
Observing and recording the behavior of animals or people
in their natural environment.
Courtesy of Gilda Morelli
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Descriptive Research: Survey
Survey:
A technique for gathering the attitudes, opinions or
behaviors of people usually done by questioning a
representative, random sample of people.
It would be costly and difficult to interview or question
every member of a target population. Instead,
researchers study a “sample” which is only part of the
target population.
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Survey
Random Sampling
Individuals are selected by chance
from the target population.
If each member of a population has
an equal chance of inclusion into a
sample, it is called a random sample
(unbiased).
If the survey sample is biased, its
results are not valid.
The fastest way to know about the
marble color ratio is to blindly
transfer a few into a smaller jar and
count them.
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Population
All the cases in a group, from which samples
may be drawn for a study. The whole group
you want to study.
Random Sample
A sample that fairly represents a population
because each member has an equal chance
of inclusion.
Remember…before believing survey findings,
think critically: consider the sample!
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Representative Sample
When conducting a study, a researcher selects a relatively
small group of participants (a sample) from an entire
population of all possible participants. Ideally, the
researcher would have participants with characteristics that
closely match the characteristics of the whole population this is called having a Representative Sample.
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Wisdom of the crowds
• watch wisdom of the crowds
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Descriptive Methods
Summary
Case studies, surveys, and naturalistic
observation describe behaviors.
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Correlational Research
Once psychologists have made their observations, they
must analyze and interpret them. One method they use is
correlation, which is a measure of how closely one thing is
related to another.
Correlational research examines the relationship between
two sets of observation. For example, students grades and
the number of hours they sleep.
Correlation describes a relationship between two things. It
does not mean, though, that one things causes the other.
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Correlations
Think about the following…
Constable Sinclair finds that as ice cream
consumption increases, the crime rates
increases. As people eat less ice cream,
the crime rate decreases. What explains
this relationship?
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Ice cream and Crime
• Is it a connection or is there something these two
variables have in common? Both ice cream
consumption and crime rate are related to a third
variable: outside temperature. When it is warm
outside, as it is in summer, people enjoy the treat of
ice cream and more crimes are committed, because it
stays light longer, people are outdoors, and windows
are kept open. During the long, dark winter months,
people eat less ice cream and fewer crimes are
committed.
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Correlation
It is important to remember that a correlation describes a
relationship between two things. It does not mean, though,
that one thing causes the other.
In some cases, a third factor exists that may account for the
positive correlation. Correlations do not identify what
causes what.
For example, although you might detect a positive
correlation between sunny days and your cheerful moods,
this does not mean that sunny days cause good moods.
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Scatterplots
Perfect positive
correlation (+1.00)
Scatterplot is a graph comprised of points that are
generated by values of two variables. The slope of the
points depicts the direction, while the amount of scatter
depicts the strength of the relationship.
Positive correlation - as one variable goes up, the other
variable goes up. (Both variables increase together or
decrease together)
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Scatterplots
Perfect negative
correlation (-1.00)
No relationship (0.00)
Negative Correlation – one variable increases while the other decreases.
No Correlation – no relationship…neither increase or decrease
The Scatterplot on the left shows a negative correlation, while the one on the
right shows no relationship between the two variables.
The stronger the correlation between two things, the more closely those two
things are relate.
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Correlation
When one trait or behavior accompanies
another, we say the two correlate.
Indicates strength
of relationship
(0.00 to 1.00)
Correlation
coefficient
Correlation Coefficient is a
statistical measure of the
relationship between two variables.
r = + 0.37
Indicates direction
of relationship
(positive or negative)
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Limits of Correlation
Correlation describes relationships. It does not, however, reveal
cause and effect. It can however predict future behavior.
Example:
You are conducting a study in your school and discovered a
positive correlation between students’ grades and their level of
involvement in extracurricular activities. In other word, you found
that students who earn high grades in their classes also
participate heavily in extracurricular activities.
Does this mean that earning high grades causes students to
become involved in extracurricular activities or that involvement
in extracurricular activities causes students to earn high grades?
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Experimentation
Why would a researcher choose experimentation
over other research methods?
Experimentation enables the investigator to control
the situation and to decrease the possibility
that unnoticed, outside variables will influence
the results.
Like other sciences, experimentation is the
backbone of psychology research.
Experiments isolate causes and their effects.
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Watch Experimental Design
• The Experiment
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Designing an Experiment
In designing experiments, psychologist think in terms of
variables, conditions and behaviours that are subject to
change.
There are two types of variables: independent and
dependent.
Independent variable – the variable the experimenters
change or alter so they can observe its effects.
Dependent variable – is the one that changes in relation
to the independent variable.
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Independent and Dependent Variables
• What is the difference?
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Independent Variable
An Independent Variable is a factor manipulated
by the experimenter. The effect of the independent
variable is the focus of the study.
For example, when examining the effects of breast
feeding upon intelligence, breast feeding is the
independent variable.
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Dependent Variable
A Dependent Variable is a factor that may change
in response to an independent variable. In
psychology, it is usually a behavior or a mental
process.
For example, in our study on the effect of breast
feeding upon intelligence, intelligence is the
dependent variable.
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Control and Experimental Groups
Experimental Group – the group to which an independent
variable is applied
Control Group – the group that is treated in the same way
as the experimental group except that the experimental
treatment (the independent variable) is not applied
A control group is necessary in all experiments. By
comparing the way control and experimental groups
behaved in an experiment the researchers can determine
whether the independent variable influences behavior and
how it does so.
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Control and Experimental Groups
• What is a Control Group? What is an Experimental
Group?
• And Confounding variables
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An Experiment
• 1. Dr. Baldwin studies the effects of marijuana on
memory she designs an experiment where half the
group is receiving THC ( the active ingredient in
Marijuana) and the other group gets oregano. The
subjects are all given the same list of words to study
while they are smoking the substances. Recall is
tested 1 hour later.
IV: THC
DV: Memory
Experimental group: those receiving THC
Control group: those receiving oregano
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An Experiment
• 2. Dr. McMurphy performs an experiment to learn if
room temperature affects the amount of aggression
displayed by High School students under crowded
conditions in a psychology classroom. What is the
independent variable?
a.
b.
c.
d.
The amount of aggression
Crowding
Room temperature
The psychology classroom
C Room Temperature
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Identify the IV and DV
• A recent report found that blueberries enhanced the maze
running performance of mice.
• We are studying whether or not a new vitamin supplement
helps boost memory retention.
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Here is your opportunity to describe an experiment of your
own creation:
I would like to investigate the effects of ____________________
on this behavior: _____________________
Half my participants would _______________________________
while the others would ___________________________________
Independent Variable I am manipulating is: ____________________
Dependent Variable or data I am collecting is: _____________________
Experimental Group (that I am most interested in) is: _________________
Control Group (that is for comparison purposes) is: ___________________
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Experimental Control
Random Assignment: The use of chance to assign
subjects to experimental and control groups.
(For example, how do we know that the people in one group aren’t more
intelligent than those in the other group?)
Double Blind Procedure: Experimental procedure in
which both the research participants and the research
staff are “blind” or unaware of whether subjects are in
the experimental group or the control group. This keeps
researchers from unconsciously influencing subjects.
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Placebo
Placebo is an inert substance having no affect on
the body. Often called a sugar pill.
Placebo effect happens when the person believes
that the pill has an affect and behaves as if it has an
affect.
Self-fulfilling prophecy is a prediction that
prompts people to act in ways that make the
prediction come true.
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Videos
placebo effect
Strange powers of the placebo effect
placebo video 2
Stuff they don’t want you to know
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Expectations influence people
Self-fulfilling prophecy is a prediction that prompts people
to act in ways that make the prediction come true.
Example: In an experiment a teacher was told that his or her students
had unusually high or low ability in math. Students who were labeled
high ability improved much more in math scores than those in lowability classes. Yet, initially, all of the students were of equal ability.
WHY did this happen?
Apparently, the teacher subtly communicated her expectations to the
students. Most likely, she did this through tone of voice, body
language, and by giving encouragement or criticism. Her “hints” in
turn, created a self-fulfilling prophecy that affected the students.
Double blind procedure helps to eliminate a self-fulfilling
prophecy!
(This keeps researchers from unconsciously influencing subjects.)
Ethics in Research
Ethics are important in all research on both humans and
animals. When something is considered ethical, it means
that it is considered morally right.
Many hypotheses cannot be tested experimentally because
they are unethical or immoral.
Human Research
Human Research
Research involving human subjects must follow these
guidelines:
1. Informed consent: participants must know that they are
involved in research and be told about any potential
risks.
2. Coercion: participation must be voluntary. No one can
be forced to participate and participants can withdraw
at any time from the study.
3.
Anonymity/Confidentiality: Participants’ privacy must
be protected. The researcher must never reveal their
identities.
4.
Risk: Participants cannot be placed in any significant
mental or physical risk.
5.
Debriefing: Participants must be told the purpose of the
study and provided with ways to contact the
researchers about the study results.
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Did this experiment follow ethical
guidelines?
• Stanley Milgram Experiment
Animal Research
“Quit school? Quit school!
You wanna end up like your father? A career lab
rat?”
Animal Research
Research involving animals must follow these guidelines:
1. Clear scientific purpose: The research must answer a
specific, important scientific question. Animals are
chosen because they are best-suited.
2. Humane treatment: The animals used in the research
must be cared for and housed in a humane way.
3.
Legal possession of animals: The animals used in
research must be purchased from legal companies. If
wild animals are used they must be trapped in a
humane manner.
4.
Minimum suffering: The experimental procedures must
be designed to use the least amount of suffering
possible.
Why use animals in research?
• Biological and behavioral similarities between animals
and humans therefore we can learn things that apply to
humans
• Lifespan of most animals is shorter than that of humans,
We can study genetic effects over generations much
faster in animals than with humans
• More control over experiments with animals than with
humans
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Comparison
Below is a comparison of different research
methods.