click to play button
click to replay button
Norming 28Sept12 p1 - Flash (Large) - 20120928 01.46.55PM
X
  1. Today
  2. Slide 3
  3. Onto Norms
  4. Good old memories
  5. Standard Normal Distribution
  6. Good old memories
  7. Standard Normal Distribution
  8. Slide 7
  9. Slide 8
  10. Slide 13
  11. Slide 8
  12. Slide 14
  13. Slide 8
  14. Slide 9
  15. Slide 10
  16. Slide 9
  17. Slide 10
  18. Slide 14
  19. Slide 10
  20. Slide 14
  21. Slide 10
  22. Slide 11
  23. Slide 13
  24. Slide 11
  25. Slide 12
  26. Slide 13
  27. Slide 14
  28. Arbitrary Metrics: Some definitions Blanton, & Jaccard, J., (2006). Arbitrary metrics in psychology. American Psychologist (61), 27-41.
  29. Slide 14
  30. Slide 13
  31. Slide 12
  32. Slide 13
  33. Slide 12
00:00 / 00:00
CC
9/28/2012 Today Syllabus/Course Review A short survey Norming Overview Quickie review of the fundamentals Arbitrary Metrics What’s the big deal? Normative Comparisons The issue Examples How-to j0196060 9/28/2012 Where are YOU on the graph? What was the best score to have? 9/28/2012 Onto Norms You take the midterm. You get a score of 48. What’s the MOST important thing to know about that score? MCj00890380000[1] Norms are empirically established by determining what persons in a representative group actually do on the test. 9/28/2012 Good old memories 9/28/2012 Standard Normal Distribution M = 40; SD = 4.94 What would a raw score be if it fell at 1SD above the mean? And it is at or above what percent of the cases? 40 + 4.9 = 44.9; at or above 84.13% of cases Fun! 9/28/2012 Good old memories 9/28/2012 Standard Normal Distribution M = 40; SD = 4.94 What would a raw score be if it fell at 1SD above the mean? And it is at or above what percent of the cases? 40 + 4.9 = 44.9; at or above 84.13% of cases Fun! 9/28/2012 Where does a score of 35.06 fall? 1 SD below the mean; at or above 15.87% of the cases. What is the score and percentile of a score that is 2 SDs above the mean? 49.88; 97.72 percentile. M = 40; SD = 4.94 More Fun! 9/28/2012 What is the percentile rank of a raw score of 34? M = 40; SD = 4.94 Using the negative half of the table for the Area under the Standard Normal Curve for Values of z, we find .1131 as the cumulative probability value. PR34 = 11%. If you get a raw score of 34, you score better or equal to 11% of the sample. Link to negative z-values table. Link to positive z-values table. 11% 11% 9/28/2012 Link to last slide viewed 9/28/2012 What is the percentile rank of a raw score of 34? M = 40; SD = 4.94 Using the negative half of the table for the Area under the Standard Normal Curve for Values of z, we find .1131 as the cumulative probability value. PR34 = 11%. If you get a raw score of 34, you score better or equal to 11% of the sample. Link to negative z-values table. Link to positive z-values table. 11% 11% 9/28/2012 Link to last slide viewed 9/28/2012 What is the percentile rank of a raw score of 34? M = 40; SD = 4.94 Using the negative half of the table for the Area under the Standard Normal Curve for Values of z, we find .1131 as the cumulative probability value. PR34 = 11%. If you get a raw score of 34, you score better or equal to 11% of the sample. Link to negative z-values table. Link to positive z-values table. 11% 11% 9/28/2012 What is the percentile rank for a raw score of 47? M = 40; SD = 4.94 The cumulative area for z = 1.42 is .9222 PR47 = 92% Link to negative z-values table. Link to positive z-values table. 9/28/2012 What raw score would we expect to find at the 75th percentile? M = 40; SD = 4.94 Link to negative z-values table. Link to positive z-values table. Hint, z = .68 corresponds to a cumulative area (aka probability) of .75. 9/28/2012 What is the percentile rank for a raw score of 47? M = 40; SD = 4.94 The cumulative area for z = 1.42 is .9222 PR47 = 92% Link to negative z-values table. Link to positive z-values table. 9/28/2012 What raw score would we expect to find at the 75th percentile? M = 40; SD = 4.94 Link to negative z-values table. Link to positive z-values table. Hint, z = .68 corresponds to a cumulative area (aka probability) of .75. 9/28/2012 Link to last slide viewed 9/28/2012 What raw score would we expect to find at the 75th percentile? M = 40; SD = 4.94 Link to negative z-values table. Link to positive z-values table. Hint, z = .68 corresponds to a cumulative area (aka probability) of .75. 9/28/2012 Link to last slide viewed 9/28/2012 What raw score would we expect to find at the 75th percentile? M = 40; SD = 4.94 Link to negative z-values table. Link to positive z-values table. Hint, z = .68 corresponds to a cumulative area (aka probability) of .75. 9/28/2012 What raw score would we expect to find at the 20th percentile? M = 40; SD = 4.94 Link to negative z-values table. Link to positive z-values table. Hint: What is the z score for a cumulative area (aka probability of .20)? 9/28/2012 Link to last slide viewed 9/28/2012 What raw score would we expect to find at the 20th percentile? M = 40; SD = 4.94 Link to negative z-values table. Link to positive z-values table. Hint: What is the z score for a cumulative area (aka probability of .20)? 9/28/2012 The z-score or standard score is what type of transformation? Linear 9/28/2012 Link to last slide viewed 9/28/2012 Link to last slide viewed 9/28/2012 15 Arbitrary Metrics: Some definitions Blanton, & Jaccard, J., (2006). Arbitrary metrics in psychology. American Psychologist (61), 27-41. Metric: the numbers that the observed measures take on when describing individuals’ standing on the construct of interest e.g., self-esteem metric might range from 1 (lowest possible) to 7 (highest possible) Arbitrary Metric: A metric is arbitrary when it is not known where a given score locates an individual on the underlying psychological dimension, or how one-unit change on the observed score reflects the magnitude of change on the underlying dimension. Until psychologists know what psychological reality surrounds the different scores on a scale; the response metric is arbitrary. 9/28/2012 Link to last slide viewed 9/28/2012 Link to last slide viewed 9/28/2012 The z-score or standard score is what type of transformation? Linear 9/28/2012 Link to last slide viewed 9/28/2012 The z-score or standard score is what type of transformation? Linear