Psychologists do more than just wonder
about human behavior: they conduct
RESEARCH
Two Types of Research Used in
Psychology
 Applied
Research
– clear and practical reasons and uses for research
– If a psychologist was trying to come up with a new
behavior therapy to stop heroin use, it would be
applied research
 Basic
Research
– no immediate, real-world uses but explores
interesting questions
– Studying the differences between cultures and
physical beauty is an example of basic research
Things that make research
scientific

Research Must Be Replicable
 Must be able to be copied by others to get similar
reliable data
the best and most reliable studies are replicated
over and over
Things that make research
scientific
 Research Must Be Precise
 Meaning research has to be to the point and easily
understood
 To be precise psychologists use
 Operational Definitions
 a definition of terms so basic that when others
read your study they know exactly what you are
looking for or measuring
 Try to capture the essence of the concept so that
others can observe it
 Example – if you are trying to measure sense of
humor – how would you make it precise?
 presence of more laughter, more smiling,
greater number of laughs at jokes
Operational Definitions
• Explain what you mean
in your hypothesis.
• How will the variables
be measured in “real
life” terms.
• How you operationalize
the variables will tell us
if the study is valid and
reliable.
Let’s say your hypothesis
is that chocolate causes
violent behavior.
• What do you mean by
chocolate?
• What do you mean by
violent behavior?
What can cause research to go
wrong??
What exactly do I
mean by bias??

Bias
Any influence in research that unfairly increases the
possibility we will reach a particular conclusion

Types of Bias
Researcher Bias, Confirmation Bias, Experimenter Bias
 when researchers look for and accept evidence that
supports their beliefs and ignore or reject evidence
that prove false their beliefs
 Participant Bias (or subject bias)
 when research participants respond in a certain way
because they know they are being observed
 act how they think the researcher wants them to act

Hindsight Bias
 when researchers believe, after learning the outcome
of research, that they knew it all along
Hawthorne Effect
• the term is used to
identify any type of shortlived increase in
productivity
• Just the fact that you
know you are in an
experiment can cause
change
• So even a control group
may experience changes
and affect results of
experiment
Whether the lights were brighter or
dimmer, production went up in the
Hawthorne electric plant.
Scientific Method in Psychology
• Scientists develop theories through the
scientific method
• The scientific method is the process used in
psychology to discover knowledge about
human behaviour and mental processes
2-9
Scientific Method in Psychology
(cont’d)
• The first step is to state the problem
• Psychologists must ask questions that can be
answered
• The questions must be specific and defined in
a clear way
2-10
Scientific Method in Psychology
(cont’d)
• The second step is to develop a hypothesis
• A hypothesis is an educated guess about the
answer to the question that has been posed
• Hypotheses often emerge from theory
2-11
Scientific Method in Psychology
(cont’d)
• Step three is to design a study
• Researchers must identify key variables and
choose a suitable method for investigation
• Researchers also must consider how many
participants will be required and who the
participants will be
2-12
Scientific Method in Psychology
(cont’d)
• The fourth step is collect and analyze data
• Techniques must be selected that do not bias
the results
• Statistical methods help summarize the data
that have been collected
2-13
Scientific Method in Psychology
(cont’d)
• The fifth step is draw conclusions and
reporting results
• Researchers report results to the scientific
community by making presentations at
conferences or by publishing their findings in
a journal
2-14
Experimental Method
• Psychological research often takes the form
of an experiment
• An experiment is a procedure in which
researchers systematically manipulate and
observe elements of a situation to test a
hypothesis
2-15
Experimental Method (cont’d)
• A variable is characteristic of a situation or a
person that is subject to change or that differs
within or across situations or persons
2-16
Experimental Method (cont’d)
• The independent variable is manipulated by
the experimenter
• The dependent variable is the behaviour or
response that is expected to change because
of the experimenter’s manipulation
2-17
Experimental Method (cont’d)
• A sample is the limited number of people
researchers select to be part of the experiment
and who represent a larger group
2-18
Experimental Method (cont’d)
• An operational definition is a definition of a
variable in terms of the methods or
procedures used to study that variable
• Studying defined as 20 minutes per day over
three days is an operational definition
2-19
Experimental Method (cont’d)
• Participants are the individuals who take part
in an experiment and whose behaviour is
observed and recorded
2-20
Experimental Method (cont’d)
• The experimental group “receives” the
independent variable
• The control group is a comparison group
who are tested on the dependent variable
but do not receive the independent
variable
2-21
3 Types of Research you will
have to know!!!
Descriptive
Research
Correlational Research
Experimental Research
What is going on in this picture?
We cannot say exactly, but we
can describe what we see.
This is called…
Descriptive Research
Research Type #1
 Any type of research that describes the
“who, what, when, where” of a situation
 NOT concerned with causes or how something
works only about describing what is going on
3 Types of Descriptive Research
• The Case Study
• The Survey
• Naturalistic Observation
Descriptive Research Type #1
The Case Study
• Where one person (or situation) is observed
and studied in depth to gather information.
For example, if I wanted
to study personality and
abnormal behavior how
would a case study go
about it??
What is the strength and weakness of using a case
study to study a topic like this??
Case Studies
• A detailed picture
of one or a few
subjects.
• Tells us a great
story…but is just
descriptive
research.
• Does not even give
us correlation data.
The ideal case study is John and
Kate. Really interesting, but what
does it tell us about families in
general?
Strength
 Can study a behavior in depth and get quality
info on that case
Weakness
 The results of the case study are usually
not generalizable to the rest of the
population.
 One persons case would not be a valid representation
of the whole population
Descriptive Research Type #2
The Survey
• Uses interviews or questionnaires to gather
information like attitudes and beliefs
Has both pros and cons when used
• The Good
– Allows generalization
– Cheap and anonymous
– Can get a diverse and large
population
Survey Method: The Bad
How accurate
would a survey be
about the
frequency of
diarrhea?
• Social Desirability Bias
– Give socially acceptable answers not truth
• Volunteer Bias
– People who volunteer may not be representative of
whole population
• Problems with wording and answer options
Descriptive Research Type #3
Naturalistic Observation
• Observing and recording
behavior in natural environment
– No interacting with subjects at
all – just an observer
– “taking the lab into the field”
What are the benefits and detriments of
Naturalistic Observation?
+ = natural behavior
- = observers may see different things
- = can’t control the environment or outside factors
Field Trip
• We will stay together as we walk around the
school grounds.
• We are to stay quiet and observe
• There is nothing special set up, I just want you
to LOOK
How many signs in the hallway?
How many paw prints around the
school?
How many times did you see the
word Huskies?
How many cars in the parking lot?
Did a plane fly over?
How many people did you pass?
Research Type #2
Correlational Research
 Explores relationships or links (correlations)
between variables
 Example – mothers smoking during pregnancy is
“correlated” with increased risk of SIDS in
babies
Descriptive Research - - - describes
 Correlational Research - - - links or relationships
between things
Correlational Research
• #1 Thing to remember in Correlational Research
Correlation does not equal causation!!!!!
• It is important to understand that CR does
NOT say that one variable causes another but
rather that they are somehow related
For Example…
There is a correlation
between ice cream and
murder rates. Does
that mean that ice
cream causes murder?
Remember…correlation does
not equal causation!!!!!
We may not be able to determine
cause, but we can measure the
strength of a relationship…
• Relationship of variables is measured using
correlation coefficient
– A statistical measure (a number) of strength of
relationship of variables
• (ex. Ice cream and murder rates)
– Can vary -1.00 to +1.00 (more on this later)
• Correlations or relationships can go in two
directions
– Positive
– Negative
Types of Correlation
Positive Correlation
• The variables go in
the SAME direction.
Negative Correlation
• The variables go in
opposite directions.
Studying and
grades
hopefully has a
positive
correlation.
Heroin use and
grades probably
has a negative
correlation.
Research Type #3
Experimental Research
Explores cause and effect relationships
by manipulating and measuring variables
Eating too many Onions causes
Bad Breath
How do we explore cause and effect??
We set up, design, and run an Experiment
1.
Form a Hypothesis
– a testable prediction
2. Pick Population
•
-
The group who you are experimenting on
First by Random Selection
Then randomly assign them to one of two groups
- control group
– those who do not receive the experimental
treatment
- experimental group
– those who do receive the experimental treatment
3. Operationalize the Variables Operationalization Exercise
4. Identify Independent and Dependent Variable
Independent Variable

Factors that are manipulated in an experiment

The variable that should cause something to happen
Dependent Variable

The variable that should show the effect of
changing the IV

the way you can figure this out is …”If…then…”
If = IV then = DV
- “If students study for a quiz before going to sleep,
rather than in the morning, then they will get
higher test scores”
Experimenters try to hold everything else
constant so that the independent variable is
the cause of the observed effects but this
doesn’t always happen because of…
Independent Variable
• Whatever is being
manipulated in the
experiment.
• Hopefully the
independent variable
brings about change.
If there is a drug in an
experiment, the drug
is almost always the
independent variable.
Dependent Variable
• Whatever is being
measured in the
experiment.
• It is dependent on
the independent
variable.
The dependent variable
would be the effect of
the drug.
Extraneous or Confounding Variables
 variables that you don’t count on that could
change or influence the DV

you want to check for these to make sure they don’t mess up what
you are looking for with the IV
1. Determine the type of experiment:
Blind vs. Double Blind
- blind
– participants are kept in the dark about purpose or
about hypothesis
- double-blind
– both the participants and researcher are kept in
the dark
- placebo
– an inactive pill that has no known effect (sugar
pill)
2. Gather Data
3. Analyze Results
Hypothesis – students who are assigned to wear headphones in
study hall will have higher average grades at the end of the
quarter than those banned from wearing headphones
Sample
All Study hall students
(population)
40 students randomly selected
20 students randomly
assigned to
experimental group
Wear headphones
daily in study hall
Average grades at
the end of the quarter
20 students randomly
assigned to
control group
IV
Not allowed to wear
headphones
in study hall
DV
Average grades at
the end of the quarter
DV