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Thinking Like a Psychologist Part II. Agenda Roll call Collect Essay #2 Discuss APA Mastery Test Discuss Term Paper Theories, Falsifiability, and More.

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Presentation on theme: "Thinking Like a Psychologist Part II. Agenda Roll call Collect Essay #2 Discuss APA Mastery Test Discuss Term Paper Theories, Falsifiability, and More."— Presentation transcript:

1 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.

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 “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

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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 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 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 3 rd 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) VariablesQuiet ConditionNoisy Condition Noise Level (IV)LowHigh IQ (EV)Average Room Temperature (EV)70°82° Sex of Subjects (EV)60% Female Task Difficulty (EV)Moderate Time of Day (EV)MorningAfternoon

27 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.

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

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 (r xy )

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?


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