Ch. 2 Research Methods
Terms used in Research:
• Hypothesis: we are moving from an
educated guess to expresses a
relationship between two variables.
Example: (not the one
you can use). Music
influences
concentration in study
halls.
Operational definition: is one makes it clear how the
Researcher should go about measuring the process,
activity, or thing. EG. Hunger for example might be
defined as “hours without eating” When you word
statements carefully with an operational definition you make
it possible for others to replicate your study.
Provide an operational definition for the underlined
words
• 1. The experimenter wants to
determine how recreational drugs
affect a person's sense of humor.
•
Possible Answer: How many times the person laughs
• 2. The teacher wants to find a way to
help make Billy act more friendly
toward the other children.
•
Possible Answer: How many times Billy helps someone else
• The null hypothesis states that there is
no relationship or difference between two
sets of data. When conducting a
psychology experiment, you can either
not reject the null hypothesis (suggesting
that there is no relationship between the
variables) or reject the null hypothesis
(suggesting that there is a relationship
between the variables).
• For example, let's suppose that you are
conducting an experiment on the effect
of sleep deprivation on math scores. Your
hypothesis is that students who receive
less than five hours of sleep the night
before a mathematics exam will do worse
than students who sleep for more than
five hours. After performing your
experiment, you find that there is a
statistically significant relationship
between sleep deprivation and math
scores, which means that you can reject
the null hypothesis.
Theory:
http://www.youtube.com/watch?v=2lXh2n0aPyw
• explanation of some aspect of the natural world that is
acquired through the scientific method, and repeatedly
confirmed through observation and experimentation …Aims to
explain
Variables are what you are manipulating in
your experiment.
http://tytusblog.blogspot.com/2009/08/engineers-make-better-models-of.html
Independent variables: What you are controlling in
the experiment.
Dependent variable: outcome that is affected by
independent variable.
• Experimental Group: Receives Treatment
• Control Group: receives no treatment
Validity and Reliability
• Valid:
it is accurate
• Reliable:
It can be replicated
Double Blind vs. Single Blind
• Placebo: “sugar pill” that is given
and the patient believes to be the real
thing.
Sampling
When conducting research, it is
almost always impossible to study
the entire population that you are
interested in. As a result,
researchers use samples as a way
to gather data. A sample is a
subset of the population being
studied. It represents the larger
six-sigma-material.com
population and is used to draw
inferences about that population.
http://mips.stanford.edu/courses/stats_data_analsys/lesson_1/234_0_a.html
A BAD SAMPLE
Finding the average height of men or
women by using basketball players for
your sample. Give me a few more.
• Random Sample: equal chance of
being picked.
• Random Assignment: Equal chance of
being assigned to a group.
Hurdles we have to overcome in
research.
• Confirmation Bias: A tendency for
people to accept information that
confirms what they want believe
Psych335 - Confirmation Bias - Team 16
http://www.youtube.com/watch?v=fc0tiNGi8jw&feature=related
• We tend to think we
Overconfidence: know more than we do.
For Example:
Some quizzes, people rate their
answers as "99% certain" but are
wrong 40% of the time.
A person who thinks his sense of
direction is much better than it
actually is.
A person who thinks he is much
smarter than he actually is.
Hindsight Bias
Hindsight bias: refers to the tendency people have to view events as
more predictable than they really are. After an event, people often
believe that they knew the outcome of the event before it actually
happened.
•
http://www.google.com/imgres?imgurl=http://www.nixlab.net/blog/IMG/Hindsight.jpg&imgrefurl=http://www.nixlab.net/blog/&usg=__ f8Bb5dXyhMSq_cgPTXQXgL
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Examples of Hindsight Bias
Imagine that you receive a letter from a publisher that states that the
publisher is going to publish your short story. You tell a friend that you
knew that they would publish it.
• Hawthorne Effect: Experimenter Bias:
Just knowing you are participating in a
study can change the outcome. Pg. 43
http://www.youtube.com/watch?v=IxZoxN5IjFE
http://www.propagandaposters.us/poster11.html
Can I just start any old research project I want to?
No, I need permission from the IRB first.
Institutional review board. They make sure you
are following all ethical guidelines. Why do we
have to have this? There have been many
unethical studies done.
During WWII the Nazi’s conducted
some very unethical studies.
Many of their subjects died during
theses experiments. What you
need to know is:
1. These people were denied the
principles in the Belmont Report
including being asked to
participate.
• Milgram Study (1963): The Milgram study
involved instructing subjects to administer
electric shocks to a study confederate in
response to poor performance. The subject
believed that he/she was involved in a study
about learning and memory with each shock
intended to affect the learning process. The
confederate pretended to be hurt by the shock
- in some cases, to the point of losing
consciousness; however, he/she did not really
feel any shock. The study objective was to
assess obedience to authority. This study
resulted in significant psychological stress for
some subjects including sweating, trembling,
stuttering and serious seizures in three
subjects. The question of whether this study
was ethical remains open to debate among
scholars today.
• http://www.youtube.com/watch?v=BcvSNg0H
Zwk
The Monster Study
• A Speech Experiment where Wendell Johnson
rounded up some orphans and separated
them into two groups. There were 22 young
subjects, 12 of whom were non-stutterers.
Half of the group experienced positive
teaching whereas the other group dealt with
negative reinforcement.
• No one in either group became stutterers at
the end of the experiment, but those who
received negative treatment did develop many
of the self-esteem problems that stutterers
often show.
http://www.highestfive.com/mind/5-unethical-psychexperiments/
• Stanford Experiment
• A group of men
volunteered for a study
and were given the roles
of prisoners or guards.
In a short time the
guards took it upon
themselves to start
trouble with the
prisoners and the
experiment got out of
hand. Lesson in “the
Lucifer” Effect. How
good guys turn bad.
https://www.youtube.com/
watch?v=RKW_MzREPp4
• Robbers Cave Experiment (Lord of the Flies)
22 eleven-year old boys were randomly separated
into two groups and taken to a summer camp in
Robbers Cave State Park, Oklahoma. The groups
were housed in separate cabins and neither group
knew of the other’s existence for an entire week.
The boys bonded with their cabin mates during that
time. When the two groups were introduced, they
began to exhibit signs of verbal abuse. To increase
the conflict between the groups, the experimenters
made them compete against each other in a series
of activities. More hostility ensued until the groups
refused to even eat in the same room. The final
phase of the experiment involved turning the rival
groups into friends.
The fun activities the experimenters had planned like shooting
firecrackers and watching movies did not initially work, so they created
teamwork exercises where the two groups were forced to collaborate. At
the end of the experiment, the boys decided to ride the same bus home,
demonstrating that conflict can be resolved and prejudice overcome
through cooperation.
Tuskegee Syphilis Study: In
1932, the Public Health Service enrolled
several hundred syphilitic black males to
document the effects of the untreated
disease over time. Tuskegee was chosen
because approximately 40% of the male
population of the town was infected with
the disease. Treatment was withheld from
study subjects when penicillin was
accepted as the treatment for syphilis in
1943. This study was stopped in 1973 but
not before many subjects became seriously
ill, transmitted their disease to others or
died. This study exemplifies unfair subject
selection practices (syphilis can potentially
affect all human beings and is not limited
to African American males), denial of
informed consent and excessive risk in
relation to study benefits.
• When doing a Research study the first step is to get
permission from the IRB:
• Protection of Participants Privacy Consent Withdrawal,
Confidentiality Deception Debriefing
• Write a brief description of each:
• 1. Protection from Harm:
• 2. Debriefing:
• 3. Privacy:
• 4. Informed Consent:
• 5. Deception:
• 6. Right to Withdrawal:
• Animal Research: YES: Otherwise important issues could not
be investigated. Relativity little animal research involves pain
or harm.
•
NO: Animals are entitled to the same rights
as humans. Animal studies are often trivial or may not apply
to humans.
Methods of
Research
Experimental Method
http://www.youtube.com/watch?v=6EjJsPylEOY
• Done in a lab.
• Good: You have control over your environment, can determine
the cause and effect of an experiment.
• Bad: You don’t see behaviors in their natural surroundings.
Correlational Research
• Research project that investigates the degree to
which two variables are related to each other.
• 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 does
NOT mean
Causation!!
Good: Determines relationship between 2 variables. Predicts future
behavior.
Bad: Will uncover a relationship but that does not mean it is the cause
Naturalistic Observation: Research tool in
which a subject is observed in its natural
habitat without any manipulation
BAD: you
have to avoid
disturbing
what you are
studying.
Experimenter
Bias.
Good: Let’s you
observe in a
participants natural
setting.
http://www.youtube.com/watch?v=k5Q6-hh49mU
Case Studies
An intense study of a person or group. Diaries,
Tests, and interviews.
Pros: Rich description of
subject, easy to control
Cons: Observer bias,
difficult to summarize
subject's experience
Survey Says…
•
We like Survey’s because:
1. They are cheap
2. you can get a large
amount of information
quickly.
We don’t like Survey’s
because:
1. Danger of participants
putting the wrong answers.
http://www.youtube.com/watch?v=iejf3YZboQ8
Longitudinal Studies
http://www.google.com/imgres?imgurl=http://www.cfr.nichd.nih.gov/images/children_linedup2.jpg&imgrefurl=http://www.cfr.nichd. nih.gov/longitudinal.html&usg=__w_lHT2
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59
Data is taken from a group over a period of time.
Good: allows researchers to look at changes over time.
Bad: require enormous amounts of time and are often quite expensive. Because
of this, these studies often have only a small group of subjects, which makes it
difficult to apply the results to a larger population.
Cross-Sectional Studies
• Data is collected from groups of
individuals of different ages and
compared.
http://www.google.com/imgres?imgurl=http://goodhealth.freeservers.com/Indonesia_kids_smoking.jpg&imgrefurl=http://snusnews.blogspot.com/2009_06_07_archive.html&usg=__oeZOXLzTwb1zO0kgdosS5qe_rCU=&h=351&w=468&sz=29&hl=en&start=132&zoom=1&t
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Pros: Much faster than a longitudinal study, and can be done with a much
larger sample size.
Cons: Not as much in-depth data can be obtained from each individual,
different experiences from different people in the group may lead to
conflicting data.
• How can math and psychology be
related?
Statistics: A branch of math that summarizes
and makes meaningful inferences from the
data.
http://www.google.com/imgres?imgurl=http://pix.motivatedphotos.com/2009/8/26/633868570471027490STATISTICS.jpg&imgrefurl=http://www.motivatedphotos.com/%3Fid%3D34720&usg=__v2u198pP5mA5uxBs2v5cCmV4Szo=&h=600&w=800&sz=70&hl =en&start=70&zoom=1&
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Measures of Central Tendency
 Mode
 the most frequently occurring score in a
distribution
 Mean
 the arithmetic average of a distribution
 obtained by adding the scores and then
dividing by the number of scores
 Median
 the middle score in a distribution
 half the scores are above it and half are
below it
 Frequency of distributions:
 List of scores ordered from highest to
lowest. Typically, made into a bar graph.
Measures of Variation.
How do we determine the variation of a
distribution of scores?
 Range
 the difference between the highest and lowest
scores in a distribution
 Standard Deviation
 a computed measure of how much scores vary
around the mean
 Statistical Significance
 a statistical statement of how likely it is that an
obtained result occurred by chance
Much psychological data can be
represented in a graph called a
normal distribution that is shaped
like a symmetrical bell. Most scores
fall in the center with a few on the
outside called outliers.
Would you like for your for your grades to
based on the “bell curve”? Why or why not?
What does being “normal” mean to you? Do
people who have always lived in the United
States like being thought of as “normal”? Why
or why not?