Presentation on theme: "Thinking Like a Psychologist Part II"— Presentation transcript:
1Thinking Like a Psychologist Part II PSYC 200 Week #8Thinking Like a Psychologist Part II
2Agenda Roll call Collect Essay #2 Discuss APA Mastery Test Discuss Term PaperTheories, Falsifiability, and MorePlan for next week / Announcements
33 Characteristics of Science Systematic EmpiricismMaking 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:
4Examples teach us what?Get into groups and discuss your assigned example.Be sure to discuss:The details / history of the exampleWhat principle the example illustratesWhy its important to psychologistsExample List:Little Green MenBirth controlling toastersAmazing RandiGoldbergerClever Hans & Facilitated Communication
5Theories & 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?FalsifiabilityHypothesis“Specific predictions derived from theories” (Stanovich, 2010, p. 21)Testable predictions.
6The Falsifiability Criterion What is falsifiability?A property of a scientific theoryThe theory’s ability to be incorrectA theory or prediction that cannot be wrong is not falsifiable – and therefore, not scientificPick 5 volunteers
8Constructs, 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.
9EssentialismThe 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.
10OperationalismThe 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 viewAn increased level of oxytocin present in the person’s pre-frontal cortexGravity 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
11Operational Definition Practice Let’s try making some operational definitions of these constructsAnxietyReading abilityGood driving skillsDepressionIntroversionHunger
12Reliability and Validity Reliability: consistency over time or situationsTest-retest reliabilityInter-rater reliabilityValidity: 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.
13Testimonials and Case Studies How to think straight about them…
14Case Studies An in-depth study of one particular subject Gives a detailed portrayal of one person’s experienceThe study’s purpose is to present reality as it happens (whether good or bad)Subject to peer review and public scrutiny from the scientific worldUseful for the early stages of investigation – helps uncover variables, issues, etc.
15TestimonialsAn individual’s personal experience to show support for a product, treatment, or truth.A person gives a detailed portrayal of his/her experienceThe 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.
16What’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 EffectThe Vividness Problem
17Placebo Effect People get better without treatment/therapy They “think” they’re getting treatmentIn 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.)
18Vividness ProblemA 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 accidentPlane flight vs. car rideTestimonials are often vivid, moving accounts of an individual’s experiences—these tend to be persuasive (but are worthless to prove a claim).
19PsuedoscienceClaims of truth and reality that claim to be rooted in science, but are NOT.AstrologyGraphologyPsychic ReadingsBiorythmsPsychoanalysisMuch of the self-help literatureMisdirects, misinforms, misguidesIs NOT Psychology
20Correlation and Causation A common misconception
21Relationship vs. Cause2 things can be related WITHOUT one causing the otherShoe size and heightIce cream sales and crime ratesSAT scores and college performanceSynonyms for “related”X predicts YX correlates with YX varies with YIndividuals with high X have high Y (or low)
22Relationship vs. Cause Incorrect words when things are only related X causes YX leads to YX increases Y (misleading)When reading or conducting relational research, must be careful in interpreting results. NO CAUSAL INFERENCE ALLOWED.
23Correlational 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 finalToasters and pregnancyCell-phone use and cancer (maybe)
24Correlation’s Problems When 2 variables are correlated, one cannot establish a causal link w/o more research.Correlation doesn’t prove causalityThe 3rd variable problemGoldberger eats S!-!|TDisease was correlated to poor sanitationDisease was correlated to poor nutritionPoor sanitation was correlated to poor nutritionThe Directionality ProblemOne cannot determine, from correlation, which causes which. (self-esteem and academic performance)
25ControlNecessary to make causal inferences and rule out alternative explanationsWhen a researcher holds everything in 2 (or more) different situations constant except for a particular variableRequires that we separate and individually control variables that may naturally occur togetherThen if the outcome changes, the only explanation is the variable that changed…Outcome = Dependent VariableManipulated variable = Independent Variable
26Control (cont’d) Variables Quiet Condition Noisy Condition Noise Level (IV)LowHighIQ (EV)AverageRoom Temperature (EV)70°82°Sex of Subjects (EV)60% FemaleTask Difficulty (EV)ModerateTime of Day (EV)MorningAfternoon
27Control (cont’d) The Control Group Examples of importance A group of participants that receives no (or alternative) treatmentWhy important?Examples of importanceClever HansFacilitated CommunicationSeparation of VariablesMust rule out alternative explanations; therefore must create artificial situations where variables that naturally occur together are teased apart.
29Research MethodsThere are 6 basic categories of scientific method that virtually all research falls intoResearchNon-ExperimentalExperimentalNaturalistic ObservationQuasi-ExperimentalField StudyExperimentalSurveyRelational Research
30Research Methods – Naturalistic Observation Addresses most basic scientific question: “What is out there?”Requires operational definition of events to be observedObserver must be unobtrusive, and design must be nonreactive
31Research Methods – Field-Based Research Like naturalistic observation, conducted in real-world settingsGoal is to establish natural relations among eventsObserver must be unobtrusive, but methods are intentionally reactive
32Research Methods – Survey Research Appropriate to the study of private behaviorsTwo primary styles:Interviews (structured/unstructured)Questionnaires (structured/unstructured)
33Research Methods – Relational (Correlational) Research Goal to verify systematic (usually linear) relations among eventsStrengths/directions of relationsgenerally expressed in form of correlation coefficient (rxy)
34Research Methods – True Experiment Goal: to establish a cause-effect relationship among eventsDoes 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?
35Research Methods – True Experiment Requires:random assignment of participants to at least two equivalent conditionsmanipulation 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)
36Research Methods – True Experiment Concludes:if groups are NOT equivalent with respect to DV, andif the difference between the groups is so big it probably did not happen by chance, thenmanipulation of the IV caused the difference in the DV
37Research Methods – Quasi-Experiment Goal also to establish cause-effect relations among eventsRequired when random assignment is not possible, becausemust use pre-existing groups, orIV impossible to manipulate directly, orIV unethical/illegal to manipulate directly
38Research Methods Review Name 6 categories of scientific researchWhich method of research can be used to establish cause and effect relationships?