Data Collection

1. Data Collection 11/26/2013

2. Readings • Chapter 6 Foundations of Statistical Inference (Pollock) (pp 122-135)

3. Homework • Chapter 8 • Question 1: A, B,C,D • Question 2: A, B, C, D, E • Question 3: A, B, C • Question 4: A, B, C, D • Question 5: A, B, C, D, E, G

4. Opportunities to discuss course content

5. Office Hours For the Week • When • Wednesday 7-10 • Monday 7-1 • Tuesday 7-12 • And by appointment

6. Course Learning Objectives • Students will learn the basics of polling and be able to analyze and explain polling and survey data.

7. Data collection

8. Collecting Primary Data • Document Analysis • Direct Observation • Interview Data

9. Observation

10. Observation • What is it • Types of Observation

11. Problems of Observation • Reactivity • Ethics

12. Which Method to use?

13. The Literature Review

14. What it Should Contain • Bring the reader up to speed on the status of the research (what has been done) • Establish face validity (why I am using these variables) • Point out potential problems with previous research

15. What it should Contain • what are the main texts in this area • what are the general theories in this area • how has the question been measured in the past

16. Interview Data: The First Step Questionnaire Construction

17. Question Style • Open Ended (advantages & disadvantages) • Closed Ended (advantages & disadvantages)

18. Demographic Questions • Who are you? • These tend to be overrated • Don’t get too personal!

19. Behavior Questions • What do you do, and how often? • Knowing behavior is a good dependent and independent variable

20. Opinion and Attitude Questions • What do you think? • Easy to Answer

21. Knowledge/Factual Questions • Use sparingly

22. Question Order is Key • Intro and Filter • First Questions • Major Questions • Final Questions- demographics

23. How you should Phrase Questions • Language (be clear) • One question 1 concept

24. Information Level

25. Bias

26. Interviewer Bias • You can’t use inflections • You can’t give hints-

27. Respondent Bias • Socially Acceptable Questions • Always Remember Homer Simpson's Code of the Schoolyard • Don't tattle • Always make fun of those different from you.  • Never say anything, unless you're sure everyone feels exactly the same way you do.

28. Question Bias • Leading Questions • Honey Boo Boo • Confusing Questions • Does it seem possible or does it seem impossible to you that the Nazi extermination of the Jews never happened?

29. A bad question • 1. What do you think is the most important issue currently facing St. Edward’s University? a. Grounds keeping b. Landscaping c. Heating d. Athletic Field Maintenance

30. Info Level problem With the problems of “mad cow” disease and potential problems with the existing BGH growth hormone, do you agree that Texas Taxpayers should stop funding tests using the experimental BVT growth hormone on Texas Livestock a. Agree b. Disagree. c. Don't Know

31. Ensuring Reliability and Validity • Pre-Test • Pilot Test

32. Sampling After we write the survey, we have to select people!

33. The Source of Public Opinion Sampling

34. What is a population • The opinions of everyone in your group • The Census includes 225 Million Adults • Cost 11.8 billion dollars • Takes years to compile

35. What is Sampling? • Sampling is the technique of selecting a representative part of a population to estimate the total population

36. The Sample • A sample is considerably smaller than the total population. • Samples that are said to mirror the population are said to be representative.

37. These Numbers Have to be drawn properly… or it is not representative

38. The Concept of Sampling • Blood Tests • Food Tests

39. Collecting a sample • Population • Sampling Frame • The Sample itself

40. The Practicality of Sampling • Time • Money • Size

41. The Laws of Sampling • The Law of Large Numbers • if cost is not a major consideration it is better to collect data for ones target population than for a sample thereof • if cost dictates that a sample be drawn, a probability sample is usually preferable to a nonprobability sample. • all probability samples yield estimates of the target population.  • The accuracy of estimates is expressed in terms of the margin of error and the confidence level.

42. Why? Non-Probability Samples

43. Probability vs. Non Probability • Probability- Every Unit Has a Chance of Being Selected • Also called a random sample • Non-Probability- some units have a greater chance of selection • Usually not generalizable

44. Why Non-Probability • Very Fast • Very cheap • Difficult Populations to reach • Exploration

45. Business Uses this Extensively • Get the Product out • Focus Groups • Alternate endings • Test audiences • If it works, you expand

46. Self Selected Samples • People Choose to Be in the Sample • Certain people have much more incentive to participate

47. Straight-up Internet Surveys • These are self-selected • Big numbers mean nothing

48. The Literary Digest in 1936 • Correct in 24,28,32 • 10 million ballots distributed • 2.2 Million Responses • Alf Landon Will defeat FDR (by a landslide)

49. Why The Literary Digest was Wrong • The wrong sampling frame • Response bias • The Literary Digest goes out of business

50. Convenience Samples • Super-Fast • Pick easy targets