1. Review of Research Methods

2. Overview of the Research Process I. Develop a research question II. Develop a hypothesis III. Choose a research design IV. Collect and analyze data V. Make conclusions

3. I. Developing research questions Sources of research ideas: Theory Previous research Casual observations Extraordinary events Social problems

4. Theory Theory- A summary statement that: –organizes what is known –explains existing data –helps us make testable predictions Theories attempt to answer several questions: –How are two or more variables related? –Why is this so? –Under what conditions does the relationship exist? (Boundary conditions)

5. Developing Hypotheses A hypothesis is a testable prediction. Requires operational definition of concepts. An operational definition specifies how the researcher plans to measure a concept.

6. Research Design Qualitative research- aim is to provide a rich description of a particular phenomenon or group. –E.G., interviews. Quantitative research- aim is to quantify relationships between variables.

7. Quantitative Research A. Correlational studies: Studies that quantify the degree of relationship between two or more variables without manipulating the variables. B. True Experiments: Studies that are intended to test cause-effect relationships between variables. At least one variable is manipulated.

8. Correlational Studies Correlation coefficient ranges from –1 to +1 –Number (0 to 1) gives the strength of the relationship 0 = no correlation; 1 = perfect correlation In practice, we use the following conventions:.1 is small,.3 is medium,.5 is large –Sign (+/-) gives the direction of the relationship

9. Interpreting Correlations Correlation does not imply causation! Two problems in establishing cause- effect: –Directionality problem Does A cause B or does B cause A? –Third variable problem C may cause both A and B

10. Dealing with Correlational Problems Directionality: –Use a longitudinal design Third variable problem: –Measure the suspected third variables and use a statistical procedure to hold them constant. E.g., partial correlation, multiple regression.

11. True Experiments Independent variable- the variable that is manipulated by the experimenter. –Experimental group- treatment –Control group- no treatment Dependent variable- the variable that is measured as an outcome.

12. Two Essential Ingredients of an Experiment Random assignment- each participant has an equal chance of being in each of the groups. Holding other variables constant- the only difference between groups should be the manipulated variable: Everything else must be held constant.

13. Factorial Design Factorial design- a design in which the levels of 2 or more independent variables are completely crossed. Main effect- a statistical term meaning that, overall, an independent variable has an effect on a dependent variable.

14. Interaction Interaction- a statistical term meaning that the effect of one independent variable on a dependent variable depends on the level of another independent variable.

15. Hypothetical Results of Factorial Design

18. Evaluating Research Internal validity: the degree to which a research finding provides clear or compelling information about causality. External validity: the degree to which a research finding provides an accurate description of what typically happens in the real world. Construct validity: the adequacy of the operational definitions. Did the researchers measure/manipulate what they intended to measure/manipulate?