Unit 1 History and Methods Chapter 1 Thinking Critically with Psychological Science

Transcription

1 Myers PSYCHOLOGY (7th Ed) Unit 1 History and Methods Chapter 1 Thinking Critically with James A. McCubbin, PhD Clemson University Worth Publishers Fact vs. Falsehood 1. Human intuition is remarkably accurate and free from error. 2. Most people seem to lack confidence in the accuracy of their beliefs. 3. Often people think that psychological findings are common sense that people knew all along. 4. Even in random strings of numbers or letters, patterns that seem unlikely actually emerge. 5. Given the number of people who purchase lottery tickets, statisticians believe it is actually likely that somewhere, someone will win the lottery twice. 6. Several psychics have been subjected to scientific tests of their abilities and found to possess real paranormal powers. Methods of Science Psychologists, like all scientists, use the scientific method to construct theories that organize observations and imply testable hypotheses Basic science science for its own sake, learning to satisfy curiosity Applied science using knowledge to make a difference Pitfalls to Avoid Confidence Test Hindsight Bias * we tend to believe, after learning an outcome, that we would have foreseen it * the I-knew-itall-along phenomenon Overconfidence * we tend to think we know more than we do 1. I feel 98 percent certain that the area of the United States is more than square miles but less than square miles. 2. I feel 98 percent certain that in 2014 the population of Australia was more than but less than. 3. I feel 98 percent certain that the number of American battle deaths in the Spanish-American War was more than but less than. 4. I feel 98 percent certain that in 2008 the number of female doctorates awarded in the United States in science and engineering was more than but less than. 5. I feel 98 percent certain that in 2014 the number of operating nuclear plants in the world was more than but less than. 1

2 Scientific Attitude (aids in preventing experimenter bias) Curiosity: The need to know Skepticism: The desire to look deeper for the answers Humility: You have to be OK with having your hypothesis proven wrong The Amazing Randi--Skeptic Critical Thinking thinking that does not blindly accept arguments and conclusions examines assumptions discerns hidden values evaluates evidence Hypothesis a testable prediction must include specifics often implied by a theory Theory an explanation using an integrated set of principles that organizes and predicts observations Operational Definition a statement of procedures (operations) used to define research variables Example- intelligence may be operationally defined as the score on an IQ test Replication repeating the essence of a research study to see whether the basic finding generalizes to other participants and circumstances usually with different participants in different situations Psychologists describe behavior using case studies, surveys, and naturalistic observation Cross-sectional Studies a variety and compares them against each other Longitudinal Studies one group over a long period of time 2

3 Types of Research Types of Research Case Study Psychologists study one or more individuals in great depth in the hope of revealing things true of us all Is language uniquely human? Survey (aka Survey Method) technique for ascertaining the self-reported attitudes or behaviors of people usually by questioning a representative, random sample of people Beware of wording or phrasing Which dessert may I get you? Random Sample (selection) a sample that fairly represents a population because each member has an equal chance of inclusion (important in survey and experiments) Naturalistic Observation observing and recording behavior in naturally occurring situations without trying to manipulate and control the situation 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 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 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 factors 3

4 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 ignorant (blind) about whether the research participants have received the treatment or a placebo commonly used in drug-evaluation studies Experimental Condition (group) the condition of an experiment that exposes participants to the treatment, that is, to one version of the independent variable Control Condition (group) the condition of an experiment that contrasts with the experimental treatment serves as a comparison for evaluating the effect of the treatment Who gets Chosen?? Random Sampling (a variety of individuals from the population are selected to participate). Stratified (or Representative) Sampling (the researcher makes sure the variety proportionally reflects the population) Random Assignment assigning participants to experimental and control conditions by chance minimizes pre-existing differences between those assigned to the different groups 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 psychology it is usually a behavior or mental process Confounding Variable Unforeseen or uncontrollable events that may confuse your data Sample Experiment A teacher believes that citrus smells will increase students intelligence. She has all the teachers on the first floor use lemon air fresheners and all on the 2 nd floor to use vanilla air fresheners for the first semester. They switch for the second semester. Teachers on the third floor use no air fresheners, but have the empty containers in view. At the end of the year they get together and compare test scores from the semester exams. 4

5 Experiment Recap which were each of the following? Variables Independent Dependent Confounding Controls to Reduce Bias (including experimenter bias) Random sampling Random assignment (or grouping) Double blind (or single) Placebo replication 5