Research Methods
Experimental Research
Descriptive Methods
Correlational Research
Biological Research
Step 3- Research Design
The hypothesis must be tested by using the
appropriate research methods
‐
What type of study would best test your
hypothesis?
‐
What participants will you use?
‐
What will be the procedure of your study?
The most powerful research
method is the experiment, in
which an experimenter
manipulates and controls the
variables to determine cause and
effect.
Experimental Method
This is the ONLY research design that can
examine a single factor’s effect on a particular
behavior
A study in which the investigator manipulates
at least one variable while measuring at least
one other variable.
‐
Determines a cause and effect relationship between
variables
Step 3-Designing a Study
Variables are a condition or characteristic that is
subject to change either within situations or
individuals
There are two types of variables in every study:
‐
Independent variable:
‐ Factor that is manipulated
‐
Dependent variable:
‐ Behavior/variable that is measured
Variables
Independent Variable is the variable is
directly and purposefully manipulated by
the experimenter
‐
This is done to see how the other variables will be
affected
So, what will happen if…?
Dependent Variable is the behavior that is
measured because it is expected to change
due to the manipulation of the
independent variable.
‐
What will happen If I move all of my front row
students to the back, what will happen?
The goal of any experiment is to
learn how the dependent
variable is affected by (depends
on) the independent variable.
Identify the Variable
Independent and Dependent?
Developmental psychologists want to
know if exposing children to differing
amounts of public television improves
their reading skills.
Did you get it?
In this study, the amount of public
television is the Independent Variable
The researchers were looking to observe a
change in reading skills, which makes it the
Dependent Variable
Name the Variables!
A clinical psychologist is interested in
how heart rate is affected by viewing a
violent film as opposed to a nonviolent
film
Did you get it?
The Independent Variable is this study is the
film type (violent or nonviolent)
The change in heart rate is the behavior
observed which makes it the Dependent
Variable
Try another one
Cognitive psychologists are
interested in what types of diagrams
are easiest for people to remember
What are the Variables?
The different types of diagrams are the
Independent Variable
What behavior were the researchers
were observing? Memory, which is the
Dependent Variable
OK, Last One…
An industrial/organizational
psychologist tests to see if wearing name
tags makes employees happier with their
work
What are the variables?
The name tags are the Independent Variable
And the observed behavior was
happiness at work, which is the
Dependent Variable
Step 3-Designing the Study
Who will you study?
Participants in a study are individuals in an
experiment whose behaviors are observed.
‐
This information will produce data
‐
All have something in common which is based
on what the researcher is testing
Participants are randomly assigned to
one of two groups:
1.
The Control Group-(Comparison group)
‐
‐
2.
This group does not receive the independent
variable
It does not receive the treatment
The Experimental Group- receives new
treatment
‐
This group “receives” the independent variable
Descriptive Methods
This research method is used to observe and
record behavior without producing a casual
explanation
Types of Research
Descriptive Methods involve describing
events that already exist
- -Naturalistic Observation
-Case Study
-Surveys
This research method is used to
observe and record behavior
without producing an
explanation
Naturalistic Observation
A systematic observation what many people
do under natural conditions, without
interference.
Follow the link below to review a
very famous naturalistic study
performed by David Rosenhan
who pretended to be mentally ill to
gain admission into a psychiatric
hospital
Being Sane in Insane Places, Rosenhan (1973)
Ask questions…
Surveys are another method of
gathering data from a wide
selection of people
A study of the prevalence of
certain beliefs, attitudes, or
behaviors, based on people’s
responses to specific questions
Unfortunately most surveys rely
on self report and not all
participants are honest!
Case Study
A thorough description of the unusual
person that relies on naturalistic
observation but focuses on a single
person intensively.
‐
These are well-suited to observe unusual behaviors
or conditions
Example of a Case Study
Phineas Gage was the foreman of a railway
construction gang. On 13th. September 1848, an
accidental explosion blew his tamping iron through
his head. The tamping iron was 3 ½ feet long and
weighed 13 pounds. The tamping iron went in point
first under his left cheek bone and completely out
through the top of his head, landing about 25 to 30
yards behind him. Phineas was knocked over but
may not have lost consciousness even though most of
the front part of the left side of his brain was
destroyed.
Phineas Gage (1848)…
yes he LIVED!
Read more about Gage…why was he the focus
of a case study?
Correlational Studies
A procedure in which investigators measure the
correlation between two variables.
‐
Without manipulating or controlling either of them
Correlation: A measure of the strength of a
relationship between two variables.
Correlational Research
ExampleA researcher may examine whether a toddler’s
aggressiveness is related to the number of hours
spent in day care.
Correlational coefficient
Correlation indicates the strength and direction of
a relationship. It allows for prediction of one
variable based on the other variable.
The strength of the relationship is measured by a
correlation coefficient which ranges from +1 to -1
+1 – perfect positive correlation
‐ 0 – no correlation
‐ -1 – perfect negative correlation
‐
Three Types of Correlation
In a positive correlation, the two factors move (or vary) in the same
direction.
In a negative correlation, the two factors vary in opposite directions—
that is, as one factor increases, the other factor decreases.
Sometimes there is no relationship between two variables—a zero
correlation.
Did you get it?
Let’s play Name that
Correlation!
Answer the following questions by
identifying the correlation…either
positive, negative or none
As a child’s age increases so does
her height
Be able to justify this answer!
As a child’s age increases so
does her height
Positive correlation!
Both variables are moving in the same
direction
The more time a person
spends on a treadmill the less
they weigh
Be able to justify your answer!
The more time a person
spends on a treadmill the less
they weigh
Negative correlation
The variables move in opposite
directions
The amount of time a college
student studies and their height
in inches
Be able to justify your answer!
The amount of time a college
student studies and their height
in inches
No correlation exists
“Correlation is not causation!”
Just because there is a correlation between
tow variables does not mean that one
variable causes another.
What happens after the study is
completed and the data is
examined?
It is time to draw a conclusion
“Was I right?”
Was my prediction correct?
Researchers draw conclusions about the results
of the study. Did the information support or
oppose their hypothesis?
Don’t forget…this information MUST be
replicated to be accepted as valid.
What happens to the information
yielded in study?
If the information produced in a study
supports the original hypothesis it is published
in the scientific community in peer-reviewed
journals.
This information is what we read about in
textbooks and articles. This process allows
researchers to generate NEW knowledge!
Ethics in Research
Could the results of a study be BIASED?
A good scientific experiment also
protects against potential sources
of error from both the researcher
and the participants
Ethnocentrism and sample bias can result in
flawed data and invalid results in the study
Avoiding Bias in Research
Absolutely, YES it is possible to bias a
research study. To avoid biased
information, researchers must follow the
rules developed by the APA.
Ethics in Research
Ethics are the rules concerning proper and
acceptable conduct that investigators use to
guide their research
‐ These rules govern the treatment of animals,
humans, and the responsibilities of investigators
Participants must be informed
One rule states human participants must give
the researcher their informed consent before a
study.
Participants must be advised about the
purpose and conditions of the study- up front.
Ethics in Research
Participants cannot be coerced into doing
something psychologically or physically
harmful, or that violates standards of decency
At the end of the study, participants must go
through debriefing
Why do researchers have these rules?
History of controversial psychological
experiments that would now be considered
UNETHICAL.
Examples:
‐
Phillip Zimbardo-The Stanford Prison Study
‐
Stanley Milgram- The Perils of Obedience
Watch the follow clip and think
about why this experiment
violates ethical standards of the
APA
Milgram-Perils of Obedience
Review the following clip and
think about how this experiment
violates ethics in psychology
Why was this study unethical?
Stanford Prison Study
Next Module…
Biopsychology
‐
How is the nervous system organized?
‐
How do “brain chemicals” influence our behavior?