Presentation on theme: "The Need for Psychological Science"— Presentation transcript:
1 The Need for Psychological Science Critical Thinkingthinking that does not blindly accept arguments and conclusionsexamines assumptionsdiscerns hidden valuesevaluates evidenceThe Amazing Randi--Skeptic
2 Critical ThinkingRoadblocks to Critical Thinking: The Limits of Intuition and Common SenseWe are not passive recipients of information, we ACTIVELY INTERPRET and construct our social perceptions to fit our preconceived notions of how the world works and operates.People are basically LAZY THINKERS; willing to infer and judge by using mental “shortcuts” and otherwise not thinking too much about things.People make sense of their world by fitting it to their preconceived notions
3 The Need for Psychological Science Theoryan explanation using an integrated set of principles that organizes and predicts observationsHypothesisa testable predictionoften implied by a theory
4 The Need for Psychological Science Operational Definitiona statement of procedures (operations) used to define research variablesExample-intelligence may be operationally defined as what an intelligence test measures
5 The Need for Psychological Science Replicationrepeating the essence of a research study to see whether the basic finding generalizes to other participants and circumstancesusually with different participants in different situations
6 DescriptionPsychologists describe behavior using case studies, surveys, and naturalistic observation
7 Description Case Study Psychologists study one or more individuals in great depth in the hope of revealing things true of us allIs language uniquely human?
8 Description Survey Random Sample technique for ascertaining the self-reported attitudes or behaviors of peopleusually by questioning a representative, random sample of peopleRandom Samplea sample that fairly represents a population because each member has an equal chance of inclusion
9 Description False Consensus Effect Population tendency to overestimate the extent to which others share our beliefs and behaviorsPopulationall the cases in a group, from which samples may be drawn for a study
10 Intuition and Common Sense We are not passive recipients of information, we ACTIVELY INTERPRET and construct our social perceptions to fit our preconceived notions of how the world works and operates.People are basically LAZY THINKERS; willing to infer and judge by using mental “shortcuts” and otherwise not thinking too much about things.People make sense of their world by fitting it to their preconceived notions
11 Hindsight BiasHindsight Bias – tendency to believe that one would have foreseen it after the results are shown. “Seems like common sense.” “The answer was right there and look how obvious it was.” “I knew it all along.”EX: Research on low self-esteem or high self-esteem and susceptibility to flattery. Perception that psychological research findings merely verify our common-sense understanding
12 Hindsight BiasEX: Several weeks after a political election, voters often exaggerate their ability to have predicted the election outcome.EX: Mike’s stockbroker has informed him of substantial investment losses. When Mike tells his wife, she angrily responds, “I could have told you that your investment plan would fail.”
13 Hindsight BiasFalse Consensus Effect – we believe others agree with us more than they do. We spend most of out time with a biased sample of people, mostly those who share our attitudes and habits.EX: David Letterman ActivityEX: Conservatives think more people support conservative views than will people who are liberals.EX: You mistakenly assume that everyone around you enjoys listening to country music like you do.
14 Overconfidence Effect Overconfidence Effect – you are more confident about how quickly they can complete assignments or how well they did on a test. A result of the self-serving bias.EX: When American students start college, only 2% say there is a very good chance they will drop out permanently or temporarily.EX: Planners often exhibit overconfidence in estimating how quickly and inexpensively they can do a project.EX: Students are overconfident about how quickly they can do assignments and write papers.
15 Confirmation BiasConfirmation Bias – we seek out or notice evidence that will verify our ideas more eagerly than we seek evidence that might refute themEX: Stereotypes we holdEX: Business managers are more likely to follow the successful careers of those they once hired than to track the achievements of those they rejected.
16 Belief PerseveranceBelief Perseverance – tendency to cling to our beliefs in the face of contrary evidence.EX: Thomas believes that rich people are stuck up. His friend, Elaine, introduces him to several rich people who are not at all stuck up. Thomas still believes rich people are stuck up.EX: Coaches continue to believe that hot hands in b-ball exist
17 Illusory Correlations Both belief perseverance and confirmation bias are results of people making illusory correlations (perceived correlation that does not really exist) – when we believe there is a relationship between two things, we are likely to notice and recall instance that confirm our beliefEX: Infertile couples who adopt become more likely to conceiveEX Hot hands in b-ballEX: “Of course it rained. That is because I just washed my car!”
18 Representative Heuristic Representative Heuristic - judge a person, object, or event by how similar it is to what you imagine to be a typical representative of a category.We think that people who exhibit certain characteristics will exhibit other, related characteristics. We think that “like goes with like”EX: If I meet someone with a laid back attitude and long hair, I might assume they are Californian, whereas someone who is very polite but rigid may be assumed to be English.
19 Heuristic ExampleEX: People who were told that Linda majored in philosophy and was a social activist. Then they ranked the probability of statements about LindaLinda is a bank tellerLinda is a bank teller and a feminist80% of people rated the statement “Linda is a bank teller and a feminist” as more likely than “Linda is a bank teller”This contradicts the fact that the probability of x is greater than the probability of x and y co-occurring (when x and y are independent events)
20 Availability Heuristic Availability Heuristic – people judge the frequency of an event by how easily it is brought to mind.EX: People think jet crashes are frequent because instances of them are salient, or easily brought to mind.EX: Subjects guess that more people die from guns than asthma, cancer than stroke, murder than floods. Yet, in each case they were wrong. perhaps
21 Anchoring and Adjustment Heuristic Anchoring and Adjustment Heuristic – make judgments by starting with an initial estimate and then adjust it to yield the final answer. When people are presented with an answer to a question, they use that answer as a reference point.EX: Participants were shown a number, either 10 or 65. They were then asked to estimate the proportion of African nations in the UN. People who saw a 10 gave an average estimate of 25%. Those who saw a 65 gave an average estimate of 45%
22 Correlational Study Correlational Study -A statistical measure of relationships that organizes a set of facts and reveals how accurately one behavior predicts another.-e.g., more democratic parents have children who behave better-CANNOT prove causation-e.g., do democratic parents produce better behaved children?-e.g., do better behaved children encourage parents to be democratic?
23 Correlation Coefficient = r -Statistical calculation that describes the direction and strength of the relationship between two variables.
24 Correlation Coefficient = r -Positive correlation means when one goes up or down the other does too. Two variables change in the same direction, as x increases so does y (max +1.00)-Negative correlation: when one goes up, the other goes down and visa versa. Inverse relationship, as x increases y decreases (min –1.00)-Or not related! (~ 0.0)-The higher the absolute value of r, the stronger the relationship-Perfect correlation r = + or – 1.00-EX: r = +.37 (r – correlation coefficient+ - indicates direction of relationship.37 – indicates strength of relationship 0.00 to 1.00)
25 Negative Correlation-Negative correlation: when one goes up, the other goes down and visa versa. Inverse relationship, as x increases y decreases (min –1.00)-Or not related! (~ 0.0)-The higher the absolute value of r, the stronger the relationship-Perfect correlation r = + or – 1.00-EX: r = +.37 (r – correlation coefficient+ - indicates direction of relationship.37 – indicates strength of relationship 0.00 to 1.00)
26 ScatterplotScatterplot - a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation).
27 Illusory CorrelationA perceived correlation that does not really exist is an illusory correlation - the perception of a relationship where none exists
28 Measures of Central Tendency Summarizes a set of data by providing a representative number.Mean - the arithmetic average Median - the center score, the score that divides a data set in two Mode - the score that occurs the most
29 Measures of Variability Indicates the dispersion or spread in a set of data – tell you if the scores are very different from one another or if they cluster around the meanRange - the difference between the highest and lowest score in a set of data Standard deviation - reflects the average distance between every score and the mean
30 Scientific Method Scientific Method Scientific method - Set of rules and procedures on how to study, observe, or conduct experimentsSteps include:1. Formulate a research questionGenerated by theories - set of tentative explanations of behavior and mental processes.
31 HypothesisWorded as a hypothesis - assertion or prediction for a behavior stated as a testable proposition, usually in the form of an if-then statementcan be verified or falsifiedexamine relationships between variables –specific factors that are manipulated and measured in research.
32 Research Methods 2. Select the research method and design the study Research methods include experiments, case studies, surveys, naturalistic observationMust provide operational definitions - statement of the specific procedures used and the behaviors studied (variables) in the research
33 Collect the data3. Collect the data - direct observations, questionnaires, interviews, psychological tests, physiological recordings, and examination of archival records4. Analyze the data and draw conclusions
34 Report the findings- Professional Journals Report research in professional journalsReplication - repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding generalizes to other participants and circumstances.
35 Report the findings 5. Report the findings Report research in professional journalsReplication - repeating the essence of a research study, usually with different participants in different situations, to see whether the basic finding generalizes to other participants and circumstances.
36 Methods in Psychology Methods in Psychology Setting - field vs. laboratoryLaboratoryprovide uniform conditions for all subjectspermits elimination of irrelevant factorsmay seem artificialField researchbehavior observed in real-world settingpoor control over conditionsmeasures may be more representative of reality
37 Data Collection Methods Data collection methods - self-report vs. observationalSelf-report - procedures in which people rate or describe their own behavior or mental stateQuestionnaires/ surveysrating scales on a scale from 1 to 7 rate your opinion of …judgments about perceptionson a scale from 1 to 100 how hot is ...
38 Observational Methods Observational methods - researchers directly observe and record behavior rather than relying on subject descriptionsnaturalistic observation - researcher records behavior as it occurs naturallytests - researcher presents stimuli or problems and records responsesexperiments - researcher measures whether variables effect other variables in a controlled laboratory procedure.
39 Descriptive Study Descriptive Study Describes a set of facts Cannot be used to determine the causes of behavior
40 Natural ObservationNaturalistic Observation – method of gathering descriptive information, involves watching behaviors of interest, without interfering, as they occur in their natural environments.Advantage = obtain data about a truly natural behavior rather than a behavior that is in reaction to contrived experimental situationDisadvantage = if participants realize they are being observed, their behavior becomes unnatural; difficult and time-consuming; controls are lacking; difficult to generalize the results of the research; scientific objectivity is lost if experimenters interact with participants
41 Case StudiesCase Studies – an observation technique in which one person, group, or situation is studied in depth in the hope of revealing universal principles. Often combines observations, interviews, tests, and analyses of written records.Advantage - useful in studying rare or complex phenomenaDisadvantage – can mislead us: any given individual may be atypical and lead to false conclusions
42 SurveysSurvey – questionnaires, tests, or special interviews administered to a large, random group of people to ascertain their self-reported attitudes or behaviors.Advantage – enable researchers to describe the characteristics of a relatively small sample (a few hundred people) and then generalize that information to a larger population, quickly collectDisadvantage – easily biased (tend to hang around people like us), a small return rate means that the sample is not representative, wording of questions can have major effects on the opinions respondents express, not in-depth, not answered truthfully
43 TestsTests - measures various traits and characteristics in a population, such as intelligence, aptitude, and personality testsReliable – consistency of measurement.Test-retest reliability – comparing scores on tests taken on different occasions.Valid – degree to which test measures what it is supposed to measure
44 Experimental Study Experimental Study Experiment = Carefully controlled scientific procedure in which a group of subjects obtains a treatment and are then observed carefully to determine whether the treatment makes a difference in their behavior.Measures how variables manipulated by the experimenter have an effect on other variables.Direct way to test a hypothesis about a cause-effect relationship between factors
45 Experimental StudyAdvantages – precise control available in the experiment allows them to isolate the relationship between the independent and dependent variable and find out cause-and-effect relationships.Disadvantages – experiments are artificial and require great control Can’t be used to explore some research questions because of ethical concerns and some manipulations of variables are difficult or impossible.
46 Experimental Variables Variables – specific factors or characteristics that can vary (weight, time, distance between people, scores on a test, number of responses)Independent variablethe controlled factor in an experimente.g., democratic vs. authoritarian classroomhypothesized to cause an effect on another variabletotally independent of anything the subject doesadministered to the experimental group
47 Experimental Variables Dependent variablethe measurable behavior exhibited – before and after the administration of the independent variablee.g., cooperative behavior among studentsbehaviors or mental processes affected by the independent variableSubject variables – age, gender, race, ethnicity, cultural background, socioeconomic status, sexual orientation, disability. Must consider the impact of variables on the behavior or mental processes being studiedSituation-relevant variables - test conditions, experimenter behavior, timing
48 Experimental Design Experimental Design Experimental vs. Control – experiments must have at least two groups of subjects so that the performance of one group can be compared with the other’s:Experimental group – receives the independent variable or the treatment in an experiment
49 Control groupControl group – does not receive the independent variable, thus providing a baseline for comparison to the experimental group. (this group is identical to the experimental group in every way except that these subjects do not receive independent variable)Any difference in the dependent variable between the control and experimental groups is caused by the independent variableLevels may differ between or within peopleWithin-subject experiment - different levels of the independent variable are applied to the same subjectBetween-groups experiment - different levels of the independent variable are applied to different groups of subjects
50 Human Participants Selecting Human Participants for Research Sampling = choosing subjects for research. The subjects chosen should be representative of the population (the total of all possible cases from which a sample is selected) being studied.Random sample - every member of pop. has an equal chance of being selected for the studyStratified sample – identified subgroups in the population are represented proportionately in the sample.Random assignment - every subject has an equal chance of being placed in either the experimental or control group (even/odd, draw straws)Randomization helps avoid false results
51 CounterbalancingGroup matching – the nature of the experiment demands a certain population be used for an experiment instead of randomization.Counterbalancing – change one variable with another, i.e. if one group of depressed clients received an IV in the am and the other group received a placebo in the pm, switch times
52 Experimenter Flaws Experimenter Flaws Confounding of Variables - difficulty separating the effects of extraneous/random variables from those of the independent variable, thus confusing interpretation of the experimental dataExtraneous/Random Variables - uncontrolled factors that might have affected the dependent variable instead of or along with the independent variable (difference in subjects’ backgrounds, personalities, health, and so on, that might confound research results)Experimenter Bias / Observer-expectancy Effect - researcher affects the dependent variable by encouraging subjects to respond in a way that supports her hypothesis or experimental results
53 BIASSubject-expectancy effect - subject knows design and tries to produce expected resultTo prevent bias, psychologists use blinding - minimize expectancy by removing knowledge about experimental conditionsSingle-blind study - when subjects are kept uninformed as to the treatment they are receivingDemand characteristics – any cues in a study that suggest to subjects the purpose of the study or what the researcher hopes to find
54 PlaceboDouble-blind study - neither the experimenter nor the subjects know who has received the independent variable.Volunteer Bias – people who offer or volunteer to participate in research studies differ from people who do not.Sample bias – sample is not truly representative of the population being studied. Everyone in the population of interest did not have an equal chance of being selected to participate in a study.Use random assignment to reduce the impact of random variables on the resultsBig sample – the larger the sample, the more likely it will represent a cross section of the entire populationPlacebo Effects – placebo is a physical or psychological treatment that contains no active ingredient but produces an effect on the dependent variable because the person receiving it believes it will.
55 Quasi-ExperimentsQuasi-Experiments – Use pre-existing groups, so not able to randomly assign participants. Conducted when an experiment with adequate controls would be unethical or impossible.
56 Correlation Study Correlation Study Organizes a set of facts and reveals relationships among factse.g., more democratic parents have children who behave betterCannot prove causationDo democratic parents produce better behaved children?Correlation Study - Descriptive StatisticsUsed to describe or summarize sets of data to make them more understandableData - a collection of numerical measurements of research resultsStatistics - mathematical descriptions of data (i.e., mean, medium, range)
57 Measures of Central Tendency Summarizes a set of data by providing a representative number.Mean - the arithmetic averageMedian - the center score, the score that divides a data set in twoMode - the score that occurs the most
58 Measures of Variability Indicates the dispersion or spread in a set of data – tell you if the scores are very different from one another or if they cluster around the meanRange - the difference between the highest and lowest score in a set of dataStandard deviation - reflects the average distance between every score and the mean
59 Correlation Correlation Coefficient Statistical calculation that describes the direction and strength of the relationship between two variables. Correlations do not indicate causation.Measures whether two variables change in a related way (r)Can be positive (max +1.00) – two variables change in the same direction, as x increases so does yNegative (min -1.00) – inverse relationship, as x increases y decreasesOr not related! (~ 0.0)The higher the absolute value of r, the stronger the relationshipPerfect correlation r = + or – 1.00
60 ScatterplotScatterplot - a graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship between the two variables. The amount of scatter suggests the strength of the correlation (little scatter indicates high correlation).A perceived correlation that does not really exist is an illusory correlation - the perception of a relationship where none exists.
61 Correlation Study - Inferential Statistics Gives probability that the sample is like the world at large – draw conclusions and make inferences about what the data meanProbability means how likely something isHow likely are results like mine to occur by chance?Statistical inferencessignificant result (statistically significant) – indicates that the group differences or correlation reflects the real world rather than chance, with high probability (e.g., > .95 )not significant - results reflect chance
62 Ethical Issues in Psychological Research Ethical Guidelines – rules about research, counseling, and teaching that psychologists are required to followRight to privacyInformed consent vs. use of deceptionParticipants will behave differently if know studyDebrief participants after experiment – explain research process to participantsAnimal rights
63 Ethical Issues in Psychological Research Ethical Guidelines – rules about research, counseling, and teaching that psychologists are required to followPsych departments have review panels to screen all proposals for research - Institutional Review BoardScientists must accurately report their results, minimize subject discomfort, and prevent any long-term negative effects.Voluntary Participation - people cannot be coerced into participating in research.Right to Privacy - studies are conducted to ensure confidentiality
64 ConfidentialityConfidentiality - information will not be made available to anyone who is not directly involved in the studyAnonymity - participant will remain anonymous throughout the study - even to the researchers.Use coded numbers instead of individuals’ names and, if possible, data are reported in group form rather than individual responses
65 Debriefing Deception - not possible to tell whole truth about a study Truth would bias the subjects - behave differently if know studyHowever, involves risk to person’s self-esteemDebriefing - subjects should be told about the purpose of the research, the hypotheses being tested, the nature of the results or anticipated results, and the implications of those results for the science of psychology immediately or soon after participation.
66 Issues of RiskIssues of Risk - subjects should not be put at risk, except in cases where there is no other way to conduct research and research results offer promise to advance knowledgeSubjects have to sign consent form and can withdraw any timeRight to Service - treatment might have beneficial effects, so persons in no-treatment control group may be upset
67 Animal rights Animal rights - Animal Care Guidelines Specify the proper care and maintenance of animals, including the adequacy of space requirements, maintenance of good health, and supervision by qualified personnel.Researchers are required to make every effort to minimize the pain and discomfort of animal subjects and to seek alternative methods for their research if possible.