Transcript Modules 2 and 3 - Research Methods

That’s Not True!!!!
Research Methods in Psychology
• Cause and effect
– With an experiment, we can determine cause and
effect because we are systematically manipulating
variables
– Hypothesis-what do we think will happen in the
study?
– Independent variable(s):
– Dependent variable(s):
• Operational definitions– What do you mean by the I.V.?
– What do you mean by the D.V.?
– You need to define them so people who read
your study know what you are talking about
• Subjects:
– Population
– Sample - #s
– Random Assignment
– Experimental Group
– Control Group
• Extraneous vs. Confounding variables
– Extraneous –
– Confounding –
Flaws to look for
• 1. Internal
– The problem with internal validity is that it
becomes very difficult to generalize the results to
the rest of the population. (This can also be a
problem with case studies).
• 2. External validity-
• 3. Sampling bias -
• You need to draw a large enough sample
to represent the population under study
and then utilize random sampling
• 4. Placebo effects –
• Simply placing something in one’s mouth may
cause one to experience a placebo effect
• Placebo effects can ruin the experiment
because you cannot tell if the drug actually
had an effect on the subject or not.
•
5. Distortion of self-report-Occurs when interview
and surveys are given. The subject may lie in giving
their answers (or just stretch the truth). Can
happen in one of two ways:
•
A. Social desirability-
•
B. Response set-
(Ex- when people agree with or disagree with
everything on the survey. Most surveys are set up
to elicit positive/negative answers or so that
different choices should be made.
• 6. Experimenter bias -
• The best way to overcome this is to do a
double-blind study, in which the
experimenter does not know which
subjects are in which groups
Developmental Studies
• In order to study development of human
beings, we use several different designs:
– 1. Cross-sectional
– 2. Longitudinal
– 3. Sequential
Pros and cons with Research
Methods
• 1. Naturalistic Observation
– Pros –
– Cons –
• 2. Laboratory Experiment
– Pros –
– Cons –
• 3. Surveys
– Pros –
– Cons –
• 4. Interviews
– Pros –
– Cons –
• 5. Case Study
– Pros –
– Cons –
Ethical Issues in Psychology
• 1. Subject participation – voluntary
– Should not be forced or feel pressured
– Should be informed of any factor of research that
might make them decide not to participate
– Should be allowed to end participation at any time
and still get paid (if they are getting paid)
• 2. Subjects are not to
be harmed in any way
– Protect from
psychological and
physical harm
– Studies that may only
effect one’s emotions in a
slight way are acceptable
• 3. Deception of participants – Is it okay?
– Should be done to inform participants
– Debriefing of subject is usually necessary
• 4. Right to privacy should not be
violated
– Don’t give out information on your subjects
– If data regarding subjects will be released,
subjects must be informed and consent
must be obtained
• 5. Can we cause them harm?
– Yes to animals – but you must be able to
justify it
– Animals should be maintained in a manner
that is considered decent treatment
• 6. Approval must be obtained from the
institution that the researcher works for
– Research must be reported in an ethical fashion
– Research should be reported as soon as possible for
verification
Measures of Central Tendency
• Mean-Average of all the data
• Mode-# that appears most often. You
may have a bimodal distribution which
means that two #’s appear the same #
of times and are the most frequent #’s
in the data set.
• Median-# in the middle
• Range – subtract the lowest # from the
highest #
Correlational Studies
• While experiments
tell us about cause
and effect,
– correlational studies
do NOT tell about
causation
– they ONLY tell us if
there is a relationship
• Usually after the
fact
• Often cannot
experiment on
humans
• Follow-up may be
experiment with
animals
Correlational Research
• Look for:
– Positive vs. negative relationships
– Strength of the number
Correlational Research
• +1 –
• +.7-.9 –
• +.4-.6 –
• +.1-.3 –
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