Module 2 Research Methods AP Psychology Module 2 Research Methods

Limits of common sense and “hunches” in making decisions Why can’t we just use this? Common Mistakes with our thinking processes: --hindsight bias --overconfidence --confirmation bias --framing effect

Hindsight Bias The tendency to believe, after learning the outcome, that you knew it all along. Only after Kerry won the Iowa Primary, did people begin to say that Dean was too liberal. What would people say about Kerry if Dean won?

Scientific Method Observe some aspect of the universe. State hypothesis Test prediction by research method. Analyze results / Draw conclusions. Modify the theory in the light of your results. - Replicate Go to step 2. If needed Can results be generalized?

Hypothesis Have operational definitions. Be replicable. A tentative theory that has not yet been tested. (Predicted statement) Have operational definitions. a statement of procedures (operations) used to define research variables Example: --How are you defining intelligence for your study? Be replicable.

Types of Research Descriptive Correlational Experimental

Types of Descriptive Research The Case Study The Survey Naturalistic Observation

The Case Study Where one person (or situation) is observed in depth. What are the strengths and weaknesses of using a tragedy like the Columbine School Shootings as a case study?

The Survey Method Used in both descriptional and correlational research. Use Interview, mail, phone, internet etc… The Good- cheap, anonymous, diverse population, and easy to get random sampling (a sampling that represents your population you want to study).

Survey Method: The Bad Low Response Rate People Lie or just misinterpret themselves. Wording Effects How accurate would a survey be about the frequency of picking your nose?

Why do we sample? Need large enough to reflect target population- ways to do this? One reason is the False Consensus Effect: the tendency to overestimate the extent to which others share our beliefs and behaviors. Overgeneralize to target pop. - usu. Due to limited observation

Naturalistic Observation Observing and recording behavior in natural environment. No control- just an observer. What are the benefits and detriments of Naturalistic Observation?

Correlational Research Detects relationships between variables. Does NOT say that one variable causes another. There is a positive correlation between ice cream and murder rates. Does that mean that ice cream causes murder?

Measured using a correlation coefficient. A statistical measure of the extent to which two factors relate to one another

How to Read a Correlation Coefficient

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 correlation

Height and Temperament of 20 Men Correlation Height and Temperament of 20 Men 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 80 63 61 79 74 69 62 75 77 60 64 76 71 66 73 70 68 90 42 81 39 48 72 57 30 84 Subject Height in Inches Temperament

Scatterplot of Height and Temperament Correlation 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 Temperament scores Height in inches 55 60 65 70 75 80 85 Scatterplot of Height and Temperament

Experimental Research Explores cause and effect relationships. Headaches Eating too many bananas causes

Steps in Designing an Experiment Hypothesis Pick Population: Random Selection then Random Assignment. Operationalize the Variables Identify Independent and Dependent Variables. Look for Extraneous Variables Type of Experiment: Blind, Double Blind etc.. Gather Data Analyze Results

Experimental Vocabulary Independent Variable: factor that is manipulated Dependent Variable: factor that is measured Confounding/Extraneous Variables: factors that effect DV, that are not IV. Experimental Group: Group exposed to IV Control Group: Group not exposed to IV Placebo: inert substance that is in place of IV in Control Group

Experimentation Random Assignment assigning participants to experimental and control conditions by chance minimizes pre-existing differences between those assigned to the different groups

Analyze Results Use measures of central tendency (mean, median and mode). Use measures of variation (range and standard deviation).

A Skewed Distribution Are the results positively or negatively skewed?

Measures of Variability Range - 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

Statistics and Probability Probability means how likely something is How likely are results like mine to occur by chance? Statistical inferences significant result - reflects the real world rather than chance, with high probability (e.g., > .95 ) not significant - results reflect chance

Sources of Bias Observer-expectancy effect Subject-expectancy effect researcher has expectations that influence measurements Subject-expectancy effect subject knows design and tries to produce expected result Blinding minimize expectancy by removing knowledge about experimental conditions

Blinding Single-blind study - when subjects are kept uninformed as to the treatment they are receiving Double-blind study - when both subjects and experimenter are kept uninformed about aspects of the study that could lead to differential expectations

Ethical Issues in Psychological Research Right to privacy Informed consent use of deception Animal rights Is there justification for discomfort or harm a research procedure may produce? APA publishes ethical guidelines