AP Psychology Mrs. Waugh Unit 2 Research & Statistics

The Need for Psychological Science

Hindsight Bias : September 11, 2001

Confirmation Bias A tendency to search for or interpret information in a way that confirms one's preconceptions 2-4-6

Overconfidence Which is further west? Reno, Nevada or Los Angeles, CA

Psychology is a science. Scientific Method

Operational Definitions Defines what the researcher will be observing and manipulating. Must be measurable and manageable. HappinessPopularity IntelligenceGood music

Types of Research Methods 1. Descriptive 2. Correlational 3. Experimental

Case of Phineas Gage (1848) Descriptive Method: Case Study

Descriptive Method: Survey

Surveys Wording Effects

Descriptive Method: Naturalistic Observation  Jane Goodall and the Chimpanzees

“Social Influence on Meal Size among Moderately Obese and Non-obese Subjects”

The Hawthorne Effect Western Electric Hawthorne Factory in Chicago (1920’s)

Correlational Studies “Co-relation”

Important ! Correlation causation.

Correlation Coefficient Shows how strongly two things are related. From – 1 to + 1 ( r )

Scatterplot

Different Scatterplots

Positive and Negative Correlations  Toothbrushing and tooth decay  Education and income  Helpfulness and happiness  Education and years in jail  TV watching and grades in school

Body Lice and Good Health

Illusory Correlation

Experiments: Cause & Effect

Memorize these 24 words: Nine Plugs Army Clock Money Swap Lamp Bank Horse Hold Cell Apple Fire Color Find Ring Think Baby Lust Sway Worm Sword Rock Time

Experiments  Independent Variable  Dependent Variable  Control  Random Sample  Random Assignment

Placebo Effect

Experimenter Bias Rats in a Maze

Double Blind Studies

Confounding Variables  Have an unwanted influence on the outcome of an experiment  Might confuse, or confound, the interpretation of results.

Caffeine’s Effect on GPA

Counterbalancing How to offset confounding variables

STATISTICS

Why Do Psychologists Use Statistics? To make sense of the data they collect

Describing Data Misrepresentation may lead to incorrect conclusions.

Measures of Central Tendency  Mode  Mean  Median A single score that represents a whole set of scores.

Skew

Measures of Variation 1. Range

Measures of Variation 2. Standard Deviation How much the scores vary around the mean.

Normal Curve Most scores fall near the mean.

Regression to the Mean

Inferential Statistics Reliability: does the test yield consistent results? Significance: is the difference between the groups real or did it happen by chance?

When is an Observed Difference Reliable? 1. Representative samples are better than biased samples. 2. Less-variable observations are more reliable than more variable ones. 3. More cases are better than fewer cases.

Tiger Woods Scenario

Statistically Significant Is the difference between groups real or did it happen by chance?

Stats Question The registrar’s office at the University of Michigan has found that usually about 100 students in the Arts & Sciences have perfect marks at the end of their first term. However, only about 10 to 15 students graduate with perfect marks. What do you think is the most likely explanation for the fact that there are more perfect marks after one term than at graduation?

Ethics APA

Ethics on Human Research 1. Informed Consent 2. Confidentiality 3. Protection from harm 4. Debriefing after deception 5. Right to withdraw

Unethical Human Experiments The Tuskegee Syphilis Experiment ( )

Ethics on Animal Research The ABC’s Of Animal Research 1. Appropriate 2. Beneficial 3. Caring

Ethics for Therapy  Unfair Discrimination  Sexual Harassment  Multiple Relationships  Conflicts of Interest  Informed Consent  Privacy & Confidentiality