1. Thinking Like a Psychologist Part II
PSYC 200 Week #8
Thinking Like a Psychologist Part II

2. Agenda Roll call Collect Essay #2 Discuss APA Mastery Test
Discuss Term Paper
Theories, Falsifiability, and More
Plan for next week / Announcements

3. 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.
Systematic Empiricism: psychology is based on empiricism… what is? … However, just looking at things is not going to explain how people’s brains work, so we look at the world in a systematic way that will answer our specific psychological questions = systematic.
Replication and Peer Review:

4. 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

5. Theories & Hypotheses Theory Hypothesis
“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.

6. 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
Pick 5 volunteers

7. Operationalism and Essentialism

8. 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.

9. 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.

10. 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

11. Operational Definition Practice
Let’s try making some operational definitions of these constructs
Anxiety
Reading ability
Good driving skills
Depression
Introversion
Hunger

12. 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.

13. Testimonials and Case Studies
How to think straight about them…

14. 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.

15. 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.

16. 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

17. 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.)

18. 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).

19. 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

20. Correlation and Causation
A common misconception

21. 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)

22. 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.

23. 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)

24. 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)

25. 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

26. Control (cont’d) Variables Quiet Condition Noisy Condition
Noise Level (IV)
Low
High
IQ (EV)
Average
Room Temperature (EV)
70°
82°
Sex of Subjects (EV)
60% Female
Task Difficulty (EV)
Moderate
Time of Day (EV)
Morning
Afternoon

27. Control (cont’d) The Control Group Examples of importance
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.

28. Intro to Research Methods

29. Research Methods
There are 6 basic categories of scientific method that virtually all research falls into
Research
Non-Experimental
Experimental
Naturalistic Observation
Quasi-Experimental
Field Study
Experimental
Survey
Relational Research

30. 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

31. 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

32. Research Methods – Survey Research
Appropriate to the study of private behaviors
Two primary styles:
Interviews (structured/unstructured)
Questionnaires (structured/unstructured)

33. 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)

34. 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?

35. 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)

36. 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

37. 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

38. Research Methods Review
Name 6 categories of scientific research
Which method of research can be used to establish cause and effect relationships?