Thinking Like a Psychologist Part II
Agenda
 Roll call
 Collect Essay #2
 Discuss APA Mastery Test
 Discuss Term Paper
 Theories, Falsifiability, and More
 Plan for next week / Announcements
3 Characteristics of Science
 Systematic Empiricism
 Making observations about the world in such a way that
reveals something about how the world works.
 Replication and Peer Review (Public Knowledge)
 All scientific knowledge is to be shared with public
(other scientists) for them to review its credibility and to
attempt replication.
 Empirically Solvable Problems (Testable Theories)
 Psychologists only work to solve problems / answer
questions that are answerable by empirical methods.
Examples teach us what?
 Get into groups and discuss your assigned example.
 Be sure to discuss:
 The details / history of the example
 What principle the example illustrates
 Why its important to psychologists
 Example List:
 Little Green Men
 Birth controlling toasters
 Amazing Randi
 Goldberger
 Clever Hans & Facilitated Communication
Theories & Hypotheses
 Theory
 “An interrelated set of concepts that is used to explain a
body of data and to make predictions about the result of
future experiments” (Stanovich, 2010, p. 21)
 A systematic and falsifiable explanation for observable
events that is based on observable events.
 Theory vs. Guess?
 Falsifiability
 Hypothesis
 “Specific predictions derived from theories” (Stanovich,
2010, p. 21)
 Testable predictions.
The Falsifiability Criterion
 What is falsifiability?
 A property of a scientific theory
 The theory’s ability to be incorrect
 A theory or prediction that cannot be wrong is not
falsifiable – and therefore, not scientific
Constructs, Concepts, and
Reality
 Concept: an idea/phenomenon given a specific name
and definition—often lack strong empirical evidence
for its “existence.”
 Construct: an idea/phenomenon or collection of
related ideas/phenomena that are given a specific
name and definition. Often has strong empirical
evidence for its “existence.”
 All constructs must be operationalized to be of use to
psychology.
Essentialism
 The act or practice of trying to find the “essence” of
something.
 What does it really mean to love?
 What is gravity, really?
 Concerned with “ultimate” definitions or essential
properties.
 Not how science works—one CANNOT discover the
“essence” of something through observation.
Operationalism
 The act or practice of trying to define something by
observation.
 Love is…
 The relative degree of pupil dilation when the significant other
enters the person’s field of view
 An increased level of oxytocin present in the person’s pre-frontal
cortex
 Gravity is the force that causes all objects with mass to move
toward each other.
 Concerned with observable definitions or empirical
properties. Defining concepts using measurement.
 HOW SCIENCE WORKS – we define our terms
operationally
Operational Definition Practice
 Let’s try making some operational definitions of these
constructs
 Anxiety
 Reading ability
 Good driving skills
 Depression
 Introversion
 Hunger
Reliability and Validity
 Reliability: consistency over time or situations
 Test-retest reliability
 Inter-rater reliability
 Validity: accuracy of measurement (are you really
measuring what you claim to be measuring and only—
the whole truth and nothing but the truth)
 Construct validity – do the measures/treatments match
the construct?
 Content validity – does the measure represent all the
facets of the construct?
 Best operational definitions are both reliable and valid.
How to think straight about them…
Case Studies
 An in-depth study of one particular subject
 Gives a detailed portrayal of one person’s experience
 The study’s purpose is to present reality as it happens
(whether good or bad)
 Subject to peer review and public scrutiny from the
scientific world
 Useful for the early stages of investigation – helps
uncover variables, issues, etc.
Testimonials
 An individual’s personal experience to show support
for a product, treatment, or truth.
 A person gives a detailed portrayal of his/her
experience
 The person’s purpose is to present reality as it
happened (whether accurate or not)
 NOT subject to peer review and are often solicited
from providers of product/treatment.
What’s wrong with testimonials?
 There’s a testimonial for almost EVERY treatment,
therapy, product, or service.
 If everything works, nothing works.
 Testimonials describe what worked for ONE person—
not what works for MOST people, or what WORKS
BEST for most people.
 “My Yugo lasted for 200K miles… it was the best car I
ever had!”
 Placebo Effect
 The Vividness Problem
Placebo Effect
 People get better without treatment/therapy
 They “think” they’re getting treatment
 In studies, it is necessary to compare results of
treatment to placebo effect.
 (Without controlling for placebo effect, can’t tell
whether the thought of treatment or the actual
treatment caused changes.)
Vividness Problem
 A vivid example or case often carries more “weight”
than a series of scientific studies.
 Repeat criminals – an especially terrible crime by a
repeat offender that gets lots of media attention will
likely lead to new, tougher laws on 1st-time offenders
(even if repeat offense rate is very low)
 Abduction vs. car accident
 Plane flight vs. car ride
 Testimonials are often vivid, moving accounts of an
individual’s experiences—these tend to be persuasive
(but are worthless to prove a claim).
Psuedoscience
 Claims of truth and reality that claim to be rooted in
science, but are NOT.
 Astrology
 Graphology
 Psychic Readings
 Biorythms
 Psychoanalysis
 Much of the self-help literature
 Misdirects, misinforms, misguides
 Is NOT Psychology
A common misconception
Relationship vs. Cause
 2 things can be related WITHOUT one causing the
other
 Shoe size and height
 Ice cream sales and crime rates
 SAT scores and college performance
 Synonyms for “related”
 X predicts Y
 X correlates with Y
 X varies with Y
 Individuals with high X have high Y (or low)
Relationship vs. Cause
 Incorrect words when things are only related
 X causes Y
 X leads to Y
 X increases Y (misleading)
 When reading or conducting relational research, must
be careful in interpreting results. NO CAUSAL
INFERENCE ALLOWED.
Correlational Research
 Studies whether 2 or more variables are “related” to
each other.
 When one increases, does the other increase?
 When one increases, does the other decrease?
 When one increases, does the other stay flat?
 Things that are correlated:
 Job Satisfaction and Pay?
 Hours spent studying and score on final
 Toasters and pregnancy
 Cell-phone use and cancer (maybe)
Correlation’s Problems
 When 2 variables are correlated, one cannot establish a
causal link w/o more research.
 Correlation doesn’t prove causality
 The 3rd variable problem
 Goldberger eats S!-!|T



Disease was correlated to poor sanitation
Disease was correlated to poor nutrition
Poor sanitation was correlated to poor nutrition
 The Directionality Problem
 One cannot determine, from correlation, which causes
which. (self-esteem and academic performance)
Control
 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
Control (cont’d)
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
Control (cont’d)
 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.
Research Methods
 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
Research Methods –
Naturalistic Observation
 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
Research Methods –
Field-Based Research
 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
Research Methods –
Survey Research


Appropriate to the study of private behaviors
Two primary styles:


Interviews (structured/unstructured)
Questionnaires (structured/unstructured)
Research Methods –
Relational (Correlational) Research


Goal to verify systematic (usually linear)
relations among events
Strengths/directions of relations

generally expressed in form of correlation
coefficient (rxy)
Research Methods –
True Experiment
 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?
Research Methods –
True Experiment

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)
Research Methods –
True Experiment

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
Research Methods –
Quasi-Experiment


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
Research Methods Review
 Name 6 categories of scientific research
 Which method of research can be used to establish
cause and effect relationships?