Download Research Methods

Thinking Like a Psychologist Part 33 1/3







Roll call
Essay #2 (missing several)
APA Mastery Test – see me if questions
Review
Control, Research Methods, and more
Intuitions Test
Probability, Chance, and the Popular Image of
Psychology



Does correlation prove causation? Why or
why not?
What is the principle of faslifiability?
What are the problems with testimonial
evidence?
Necessary to make causal inferences and rule
out alternative explanations
 When a researcher holds everything in 2 (or
more) different situations constant except for a
particular variable
 Requires that we separate and individually
control variables that may naturally occur
together
 Then if the outcome changes, the only
explanation is the variable that changed…

 Outcome = Dependent Variable
 Manipulated variable = Independent Variable
Variables
Quiet Condition
Noisy Condition
Noise Level (IV)
Low
High
IQ (EV)
Average
Average
Room Temperature (EV)
70°
82°
Sex of Subjects (EV)
60% Female
60% Female
Task Difficulty (EV)
Moderate
Moderate
Time of Day (EV)
Morning
Afternoon

The Control Group
 A group of participants that receives no (or
alternative) treatment
 Why important?

Examples of importance
 Clever Hans
 Facilitated Communication

Separation of Variables
 Must rule out alternative explanations; therefore must
create artificial situations where variables that
naturally occur together are teased apart.

There are 6 basic categories of scientific
method that virtually all research falls into
Research
Non-Experimental
Naturalistic Observation
Experimental
Quasi-Experimental
Field Study
Survey
Relational Research
Experimental



Addresses most basic scientific question:
“What is out there?”
Requires operational definition of events to
be observed
Observer must be unobtrusive, and design
must be nonreactive



Like naturalistic observation, conducted in
real-world settings
Goal is to establish natural relations among
events
Observer must be unobtrusive, but methods
are intentionally reactive


Appropriate to the study of private behaviors
Two primary styles:


Interviews (structured/unstructured)
Questionnaires (structured/unstructured)



Goal to verify systematic (usually linear)
relations among events
Strengths/directions of relations
generally expressed in form of correlation
coefficient (rxy)

Goal: to establish a cause-effect relationship
among events
 Does low-fat diet cause decrease in cancer risk?
 Does exposure to violent video games cause
increase in violent behaviors?
 Does spaced study cause increase in memory
accuracy and retention?
 Do genetic variations cause sexual preference?

Requires:
random assignment of participants to at least two
equivalent conditions
 manipulation of one factor (independent variable,
or IV) in one condition (experimental), leaving it
unchanged in other condition (control)
 measurement of one other factor in both conditions
(factor called dependent variable, or DV;
measurement instrument called dependent
measure, or DM)


Concludes:
 if
groups are NOT equivalent with
respect to DV, and
 if the difference between the groups is so big it
probably did not happen by chance, then
 manipulation of the IV caused the difference in the
DV
 Goal
also to establish cause-effect relations
among events
 Required when random assignment is not
possible, because
must use pre-existing groups, or
 IV impossible to manipulate directly, or
 IV unethical/illegal to manipulate directly



Name 6 categories of scientific research
Which method of research can be used to
establish cause and effect relationships?



Gradual Synthesis Model
Great Leap
Remember, the goal of science is really to get
less and less WRONG.



Most phenomena are caused by multiple (not
just one event)
Examples?
There’s usually no “magic bullet” or “missing
key”