Unit 2 (B): Non-Experimental Research Designs Mr. McCormick A.P. Psychology

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

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

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

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

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

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

Correlation What naturally-existing correlations can you think of?

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

Height and Temperament in Men r=+0.63

Correlation Negative Correlation: Negative Correlation: Inverse relationship Inverse relationship One factor increases, while the other decreases One factor increases, while the other decreases E.g. Physical exercise and fat content E.g. Physical exercise and fat content Right: Perfect Negative Correlation (r=-1.00) 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 do you think a scatterplot would look like for two factors that are not correlated? What would its correlation coefficient be? What would its correlation coefficient be? r=0.00 r=0.00

Correlation ≠ Causation

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

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