Research Methods

1. Research Methods

2. 9th grade $16,322 Some high school $19,095 High school grad $25,081 Some college(no degree) $29,903 Associate's degree $31,358 Bachelor's degree $41,361 Master's degree $50,704 Professional degree $76,659 PhD $71,541

3. Nation X = TV's per capita Y = life exp. (years) Angola 1/200 44 Australia 1/2 76.5 Cambodia 1/177 49.5 Canada 1/1.7 76.5 China 1/15 70 Haiti 1/234 53.5 Japan 1/1.8 79 Russia 1/3.2 69 UK 1/3 76 USA 1/1.3 75.5 Yemen 1/38 50

4. X = driving credit score Y = average incurred loss per policy (1-worst 10%, 2-next lowest 10%, … , 10-best 10%) 1 $918 2 $846 3 $791 4 $707 5 $703 6 $681 7 $631 8 $584 9 $568 10 $558

5. State X = avg. spending per student (in $) Y = mean SAT Math score AL 5,885 554 AR 5,278 550 FL 6,170 499 GA 6,929 489 LA 6,037 562 MS 5,175 551 NC 6,346 499 SC 6,631 488 TN 5,687 553

6. Team X = payroll (millions of $) Y = wins in 2005 regular season NYY 208.3 95 BOS 123.5 95 NYM 101.3 83 LAA 97.7 95 PHI 95.5 88 STL 92.1 100 SF 90.1 75 SEA 87.7 69 CHC 87.0 79 ATL 86.5 90 LAD 83.0 71 HOU 76.8 89 CHW 75.2 99 BAL 73.9 74 DET 69.1 71 SD 63.3 82 AZ 62.3 77 CIN 61.9 73 FL 60.4 83 MIN 56.2 83 TEX 55.8 79 OAK 55.4 88 WAS 48.6 81 COL 48.2 67 TOR 45.7 80 CLE 41.5 93 MIL 39.9 81 PIT 38.1 67 KC 36.9 56 TB 29.7 67

7. Cleveland best value for the money How much $$ per win? Yankess = $2.18 million Tampa Bay = $440,000 Phila = $1.08 million

8. Gathering Data: • Experiments • Observations • Case Studies • Surveys • Longitudinal Studies • Cross-cultural studies

9. Samples: • Small group of the tested population • Must be representative of the larger population • To avoid bias… • Random Sample; individuals picked purely by chance (every individual has an equal chance of being selected) • Stratified Sample; individuals deliberately chosen from various sub-groups of the population. • Ethnicity, age, sex, political/religious affiliation, etc

10. Size of sample is important for accuracy… More data = better results!

11. Correlation; describes the degree of relatedness between two variables • Positive correlation; both variables move in the same direction (both up OR both down) • Ex. IQ and test scores • Attendance and grades • School cell phone use and detentions

12. Negative correlation; variables move in opposite directions. Ex. Brushing teeth and number of cavities. Life expectancy and smoking.

13. Children raised in homes with more appliances tend to perform better in school. Therefore, appliances improve intelligence. Correlation does not imply causation

14. …but it can be used to make predictions. = Lifetime earning potential education

15. Height (inches) Head Size (inches)

16. Experiments • Control the situation, environment • Decrease the influence of outside factors • Hypothesis; educated guess…establish the foundation of the experiment • Independent variable; the factor the experimenter changes to see its effect • Dependent variable; the factor that is measured to see how it was affected by the independent variable

17. Controlled experiment: Hypothesis: Red light helps plants grow better than blue light Independent variable: Color of light 24 hrs/day 12 hrs/day Dependent variable: Height of plant 1 liter of water/day 15 degrees Celcius .5 liters of water/day 20 degrees Celcius Every factor other than the independent variable should remain CONSTANT!

18. Experimental group: gets the independent variable Control group: gets treated exactly the same as the experimental group EXCEPT for the independent variable Experimental results must be replicable. Results published in a journal then reviewed and critiqued by peers. If results can be replicated and the methods and conclusions accepted by the scientific community the results are accepted as either supporting or not supporting the hypothesis. You cannot really PROVE things in science!

19. One trap to avoid in research: Self-fulfilling prophecy The researcher finds what they expect to find and ignore or overlook other important facts, data, etc. The researcher may do this unknowingly, which is why we publish results Does a researcher’s beliefs, attitudes, or feelings affect the way he or she will interpret the results of an experiment? If I work for an oil company or a utility company that uses coal, will I be as likely to believe in global warming, or will I only look at data that support what I already believe? (cherry picking the data)

20. Solution: The Double-Blind Study vs

21. Single-blind study: the test subjects are “blind”, but the researcher knows the Coke and Pepsi cups and could influence the results with body language, voice inflection, eye movements, etc. (intentional or not) Double-blind study: both the test subjects and the researcher are “blind”. If neither know the products in the cups, no improper influence could affect the results.

22. 2. Naturalistic Observation: • To understand how the subjects behave naturally • Avoid disturbing or interacting with the subjects

23. 3. Case Studies: • Intensive investigation of an individual or group • Usually focus on a particular problem or experience • Combine long-term observations (psychological tests, behavior reports, self-reports, etc) • Lacks a control group for comparison

24. 4. Surveys • Most practical way to gather data on attitudes, beliefs, and experiences from a large group of individuals quickly and easily. • Interviews; allow modification of the question if needed • Questionnaires; • Less time • Results more uniform • Eliminates influence of researcher

25. 5. Longitudinal Studies • Covers long periods of time • Study and restudy the same group at regular intervals to determine changes in behavior • Time consuming…good results may take years to obtain and publish

26. 6. Cross cultural studies • Comparisons of the way people in different cultures behave, think, feel, etc • Certain values appear to be universal, but cultural differences do affect the development of moral reasoning.