Myers chapter 1 (B): Non-Experimental Research Designs A.P. Psychology

Do-Now (In Journal) Think of a psychological phenomenon that you would be interested to research (a behavior, habit, disorder, etc.) Briefly describe how you could hypothetically carry out your research

Pre-Research Decisions Population: All the cases in a group being studied, from which samples may be drawn E.g. The entire CHS student body (2,000 students) Sample: Small group of participants, out of a total population, that a researcher studies Representative vs. Non-representative E.g. 200 CHS students

Pre-Research Decisions What might a representative sample of CHS students look like? How could we effectively get a representative sample of CHS students?

Pre-Research Decisions Random Sample: A sample that fairly represents a population because each member has an equal chance of inclusion

Non-Experimental Research Designs Naturalistic Observation: Observation of subject(s) in a natural setting without manipulating or controlling the situation (e.g. watching teenagers in a mall) Case Study: Intensive investigation of participant(s) (e.g. long-term interviews, living with participants, journals, video blogs) Survey: Information is obtained by asking many individuals a fixed set of questions (e.g. questionnaire on self-reported attitudes or behaviors)

Non-Experimental Research Designs Longitudinal Study: Studying a group of participants over a number of years (e.g. following a group of high school freshmen throughout their high school career) Cross-Sectional Study: Studying groups of participants of different ages and comparing them to draw conclusions about age (e.g. studying a group of freshmen and seniors)

Non-Experimental Research Designs Think of an example in which each of the following research designs would be most effective: Naturalistic Observation Case Study Survey Longitudinal Study Cross-Sectional Study

Correlation Correlation: A measure of the extent to which two factors vary together (and how well one factor predicts the other) Does not demonstrate causation Can be positive or negative Can be illusory (appears to be relationship where none exists) Measured with scatterplots Measured by a correlation coefficient “r” (-1 to +1)

What naturally-existing correlations can you think of?

Correlation Positive Correlation: Direct relationship Both factors increase together; Both factors decrease together E.g. Amount of sleep and GPA Right: Perfect Positive Correlation (r=+1.00)

Height and Temperament in Men

Correlation Negative Correlation: Inverse relationship One factor increases, while the other decreases E.g. Physical exercise and fat content Right: Perfect Negative Correlation (r=-1.00)

Correlation What do you think a scatterplot would look like for two factors that are not correlated? What would its correlation coefficient be? r=0.00

Correlation ≠ Causation

Review What is the difference between a population and a sample? How could one effectively create a representative sample? What is the difference between a positive and negative correlation? What are some implications of a correlation?

Homework Research Study Response #40: “Obey At Any Cost?” (Pgs. 308-317)