3The Need for Psychological Science The biases and errors of people’s everyday judgmentsillustrate the need for a scientific attitude:A. SkepticismWhere is the evidence?How do you REALLY know this?B. HumilityScientists are willing to reject their own ideas/biases, if needed.
4The Need for Psychological Science C. Critical ThinkingScientists never blindly accept arguments and conclusionsFour elementsexamine assumptionsdiscerns hidden valuesevaluates evidenceassess conclusions
5TrepanationChipping away a hole in the skull to let out evil spirits is a cure for adolescent rebellion and the thinking that leads adolescents to behave badly.Examine AssumptionsDiscern Hidden ValuesEvaluate EvidenceAssess Conclusions
6The Need for Psychological Science Hindsight Biaswe tend to believe, after learning an outcome, that we would have foreseen itthe “I-knew-it-all-along” phenomenonIntuitionDescribe your intuitive momentIn research, common sense (intuition) predicts what DID happen more often than what WILL happen.Intuition is based on common sense and experience!
7The Need for Psychological Science Overconfidencewe tend to think we know more than we dothis leads us to CONFIRM our own thoughts and ignore evidence that might disprove us (bias) – confirmation biasHave you ever ignored evidence that was contrary/different from what you believed?
8The Scientific Method Theory Hypothesis Operational Definition How can you measure or “operate” with these variables?Test the hypothesis:Girls smile more than boys.
9Operational Defintions I want to study the effects of physical contact on attachment. I want to study the effects of sugar on attention levels.
10Six steps of the Scientific Method. a. Identify the theoryb. Form an hypothesisc. Determine the variablesd. Design the experimente. Gather the dataAnalyze, conclude, and report your findingsJournals, ColleaguesMagazinesg. Replicate = Valid
11Research Methods of Psychology Case StudySurveyNaturalistic ObservationCorrelationExperimentation
12Free Response 2006 ExamPsychologists use a variety of research methods to study behavior.Three of the main research methods used are:* Case Study* Correlational Study, and* Experiment.A. Discuss the advantage of each research method listed above.B. Discuss one disadvantage of each research method listed above.Pretend you are a psychologist who will use each of the three research methods – case study, correlational study, and experiment—to determine the effect of taking Vitamin J on improving memory.C. For each method listed above, explain a key characteristic of the basic approach you could use to reach a scientific conclusion about the relationship between taking vitamin J and improving memory. You need not design a complete study.
13Case StudyGoals Met -Description (of the ONE person or ONE small group)Definition: Intensive analysis and description of an individual or a small group.Advantages: A lot of information.A rich description.Leads to ideas for future study.
14Case Study Continued … Disadvantages Examples Reflection Question #2… Observer BiasDifficult to generalize beyond single case studied
15Survey MethodGoals Met: Describe and Predict (if correlation determined from data)Definition: Asking predetermined questions using an interview or a questionnaire.
16Survey Continued … Advantages Disadvantages Lots of information Relatively low costDone in a short amount of timeRespondents might not be representative (sampling bias)Respondents might not be knowledgeable or might want to please researcher (response bias)
17Survey Problems …. Response Bias – What people SAY is often very different from what the DO. (Would you admit to everything you do/think/feel?)False Consensus – The tendency to overestimate the extent to which others share our beliefs and opinions.
18Types of Wording Effects Wording Effects – The way a question is worded affects the outcome of the survey.a. Emotionally Charged Questionsb. Limited/Biased Range of Optionsc. Biased Order of the Questionsd. Subject IgnoranceSamples Provided in Class
19Survey/Experiment Definitions Population: Larger group you wish to generalize your findings to … the group your research will benefit.Sample of Subjects: People you choose from the population to survey (study)Representative Sample: (noun)Set of subjects that represent the population (all parts … ethnicity/sex/religion/etc.)Random Sampling: (verb/procedure)Each person in your population has an equal chance of being selected for your study. Ensures a representative sample.Examples and Reflection Question #3
20Naturalistic Observation Goals Met: DescribeDefinition: Behavior is studied in its natural environment without interference from the researcher.
21Naturalistic Observation Cont. Advantages:SpontaneousNot a “lab” settingGreat ideas for future hypothesesDisadvantagesObserver BiasConfirmation BiasOne Chance – think spontaneous moment!Reflection Question #1
22Correlational Research Method Goals Met: Describe and PredictDefinition: Used to clarify the strength of a relationship among variables.
23Correlation Continued … Examples:What kind of correlation?Scatter Plots and Correlation CoefficientDark clouds and rainStudy time and test scoresSmoking and lifespanConsumption of hot cocoa and temperatureDirectionPositive – Vary togetherNegative – Vary oppositeNone – No relationshipStrength-1.00 < >+1.00+0.25-0.99+0.87
24Scatterplots, showing patterns of correlations Perfect positivecorrelation (+1.00)No relationship (0.00)Perfect negativecorrelation (-1.00)Scatterplots, showing patterns of correlations
25Correlation Continued AdvantagesDisadvantagesDescription and prediction are possible.Absolutely NO causality.Cannot explain why a relationship exists, only that there is one.Illusory Correlation(see correlation where none exists)Patterns (Idaho drivers)Random Events (shootings)Third Variables (pallegra)No Cause/Effect
26Multi-Method Approach (Eclectic) You follow a case study closelyYou notice (as part of some naturalistic observations) a correlationYou survey a similar set of subjects from the populationYou find a definite mathematical correlationYou experiment to prove cause and effect
27Experimental Method Usually the last step in the research process. May include other methods along the way.Goals Met: Explain!!Definition: The investigator manipulates one or more factors called the independent variable to observe its effect on some behavior or mental process called the dependent variable while controlling other, relevant factors called confounding variables.
28Definitions Experimentation Independent Variable (IV):The controlled or manipulated variable. The “thing” that is given or not given to the subjects. The variable whose effect is being studied.Dependent Variable (DV):The effect (behavior or mental process) being observed that is caused by the IV. The variable that may change in response to the IV.Hypothesis and Operational Definition (see previous)Experimental Group (EG):Manipulated groupReceives the treatmentReceives the IVControl Group (CG):Comparison GroupDoes not receive the IVMay receive a placebo (looks like IV, but is not have the same effect)
29Experimentation Continued … Random Sampling (verb)Get sample that represents (noun) the populationBiased SampleDoes not represent the populationEliminate Researcher Bias/Subject BiasBlind – one doesn’t knowDouble-Blind – both don’t knowRandom AssignmentRandomly assign subjects to CG and EG – to make both groups representative.
30Experimentation Continued Example – Reflection SheetPopulationIVDVCGEG
31Experimentation Continued … AdvantagesDisadvantagesConclusions can be drawn about causationExplanations are given for behaviors and mental processesCause and effectEthical considerations – any time you experiment with humans/animalsBehavior constricted to a laboratory (not always natural/realistic)
32Ethical Guidelines - APA Informed consentSubject can withdraw at any timeInformation provided for how to contact researcher afterConfidentialityExplain any misconceptions at the earliest possible time (without creating bias)If deception occurs, must remove misconceptions at the endThose working with animals/humans must be trainedGreat lengths must be taken to minimize all animal/human discomfort