对心理科学的批判性思考.ppt

1、Myers PSYCHOLOGY,Chapter 1 Thinking Critically with Psychological Science,The Need for Psychological Science,Psychologists, like all scientists, use the scientific method to construct theories that organize observations and imply testable hypotheses,The Need for Psychological Science,Hindsight Bias

2、we tend to believe, after learning an outcome, that we would have foreseen it the “I-knew-it-all-along” phenomenon Overconfidence we tend to think we know more than we do,The Need for Psychological Science,Critical Thinking thinking that does not blindly accept arguments and conclusions examines ass

3、umptions discerns hidden values evaluates evidence,The Amazing Randi-Skeptic,The Need for Psychological Science,Theory an explanation using an integrated set of principles that organizes and predicts observations Hypothesis a testable prediction often implied by a theory,The Need for Psychological S

4、cience,The Need for Psychological Science,Operational Definition a statement of procedures (operations) used to define research variables Example- intelligence may be operationally defined as what an intelligence test measures,The Need for Psychological Science,Replication repeating the essence of a

5、 research study to see whether the basic finding generalizes to other participants and circumstances usually with different participants in different situations,Description,Psychologists describe behavior using case studies, surveys, and naturalistic observation,Description,Case Study Psychologists

6、study one or more individuals in great depth in the hope of revealing things true of us all,Is language uniquely human?,Description,Survey technique for ascertaining the self-reported attitudes or behaviors of people usually by questioning a representative, random sample of people Random Sample a sa

7、mple that fairly represents a population because each member has an equal chance of inclusion,Description,False Consensus Effect tendency to overestimate the extent to which others share our beliefs and behaviors Population all the cases in a group, from which samples may be drawn for a study,Descri

8、ption,Description,If marbles of two colors are mixed well in the large jar, the fastest way to know their ratio is to blindly transfer a few into a smaller one and count them,Description,Naturalistic Observation observing and recording behavior in naturally occurring situations without trying to man

9、ipulate and control the situation,Correlation,Correlation Coefficient a statistical measure of the extent to which two factors vary together, and thus how well either factor predicts the other,Correlation coefficient,Indicates direction of relationship (positive or negative),Indicates strength of re

10、lationship (0.00 to 1.00),r = +.37,Correlation,Scatterplot 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 the amount of scatter suggests the strength of the correlation little scatter indicates high c

11、orrelation also called a scattergram or scatter diagram,Correlation,Scatterplots, showing patterns of correlations,Correlation,Correlation,Scatterplot of Height and Temperament,55 60 65 70 75 80 85,Correlation,Three Possible Cause-Effect Relationships,(1) Low self-esteem,Depression,(2) Depression,Lo

12、w self-esteem,Low self-esteem,Depression,(3) Distressing events or biological predisposition,could cause,could cause,could cause,or,or,and,Illusory Correlation,Illusory Correlation the perception of a relationship where none exists,Two Random Sequences,Your chances of being dealt either of these han

13、ds is precisely the same: 1 in 2,598,960.,Experimentation,Experiment an investigator manipulates one or more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable) by random assignment of participants the experiment controls other relevant

14、 factors,Experimentation,Placebo an inert substance or condition that may be administered instead of a presumed active agent, such as a drug, to see if it triggers the effects believed to characterize the active agent Double-blind Procedure both the research participants and the research staff are i

15、gnorant (blind) about whether the research participants have received the treatment or a placebo commonly used in drug-evaluation studies,Experimentation,Experimental Condition the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent varia

16、ble Control Condition the condition of an experiment that contrasts with the experimental treatment serves as a comparison for evaluating the effect of the treatment,Experimentation,Random Assignment assigning participants to experimental and control conditions by chance minimizes pre-existing diffe

17、rences between those assigned to the different groups,Experimentation,Independent Variable the experimental factor that is manipulated the variable whose effect is being studied Dependent Variable the experimental factor that may change in response to manipulations of the independent variable in psy

18、chology it is usually a behavior or mental process,Experimentation,Research Strategies,Design of the subliminal tapes experiment,Statistical Reasoning,Statistical Reasoning,Statistical Reasoning,Mode the most frequently occurring score in a distribution Mean the arithmetic average of a distribution

19、obtained by adding the scores and then dividing by the number of scores Median the middle score in a distribution half the scores are above it and half are below it,Statistical Reasoning,A Skewed Distribution,Statistical Reasoning,Range the difference between the highest and lowest scores in a distribution Standard Deviation a computed measure of how much scores vary around the mean Statistical Significance a statistical statement of how likely it is that an obtained result occurred by chance,Frequently Asked Questions about Psychology,Can laboratory expe