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Lecturer’s desk

s c r e e n. s c r e e n. Lecturer’s desk. Row A. Row A. 13. 12. 11. 10. 9. 8. 7. 17. 16. 15. 14. Row A. 19. 18. 4. 3. 2. 1. 6. 5. Row B. 14. 13. 12. 11. 10. 9. 15. Row B. 8. 7. 20. 4. 3. 2. 1. 19. 18. 17. 16. 6. 5. Row B. Row C. 4. 3. 2. 1.

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Lecturer’s desk

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  1. s c r e e n s c r e e n Lecturer’s desk Row A Row A 13 12 11 10 9 8 7 17 16 15 14 Row A 19 18 4 3 2 1 6 5 Row B 14 13 12 11 10 9 15 Row B 8 7 20 4 3 2 1 19 18 17 16 6 5 Row B Row C 4 3 2 1 15 14 13 12 11 10 9 19 18 17 16 Row C 8 7 6 5 21 20 Row C Row D 20 19 18 17 22 21 4 3 2 1 16 15 14 13 12 11 10 9 Row D Row D 8 7 6 5 21 20 19 18 Row E 23 22 4 3 2 1 6 5 16 15 14 13 12 11 10 9 Row E Row E 8 7 17 21 20 19 18 Row F 23 22 4 3 2 1 Row F 6 5 17 16 15 14 13 12 11 10 9 Row F 8 7 22 21 20 19 17 16 15 14 13 12 11 10 9 Row G Row G 8 7 24 23 18 4 3 2 1 6 5 Row G 16 20 19 18 17 Row H 22 21 4 3 2 1 15 14 13 12 11 10 9 Row H 8 7 6 5 Row H table Row J Row J 25 24 23 22 1 18 table 9 6 26 5 20 19 21 13 8 7 14 26 25 24 23 4 3 2 1 27 5 20 22 21 14 13 12 11 10 9 6 18 17 16 15 Row K Row K 8 7 19 27 26 25 24 4 3 2 1 19 18 28 5 20 23 22 21 14 13 12 11 10 9 6 15 Row L Row L 8 7 17 16 4 3 2 1 27 26 25 24 22 21 15 Row M Row M 5 28 23 20 19 14 13 12 11 10 9 6 18 17 16 8 7 22 21 29 28 27 26 4 3 2 1 20 23 19 15 14 18 17 16 25 24 30 5 13 12 11 10 9 6 Row N Row N 8 7 29 28 27 26 22 21 30 4 3 2 1 20 23 19 15 14 18 17 16 25 24 5 13 12 11 10 9 6 Row P Row P 8 7 29 28 27 26 39 38 37 36 30 4 3 2 1 32 31 23 22 21 - 15 14 25 24 40 5 33 35 34 13 12 11 10 9 6 Row Q 8 7 Physics- atmospheric Sciences (PAS) - Room 201

  2. Introduction to Statistics for the Social SciencesSBS200, COMM200, GEOG200, PA200, POL200, or SOC200Lecture Section 001, Fall, 2012Room 201 Physics and Atmospheric Sciences (PAS)10:00 - 10:50 Mondays, Wednesdays & Fridays. Welcome Please double check – Allcell phones other electronic devices are turned off and stowed away http://www.youtube.com/watch?v=oSQJP40PcGI

  3. Schedule of readings Before next exam (November 9th) Please read chapters 7 - 14 Please read Chapters 2, 3, and 4 in Plous Chapter 2: Cognitive Dissonance Chapter 3: Memory and Hindsight Bias Chapter 4: Context Dependence

  4. Please click in My last name starts with a letter somewhere between A. A – D B. E – L C. M – R D. S – Z

  5. Use this as your study guide By the end of lecture today10/31/12 Logic of hypothesis testing Steps for hypothesis testing for t-tests How are t-tests similar to z-tests How are t-tests different from z tests Levels of significance (Levels of alpha) what does alpha of .05 mean? what does p < 0.05 mean? what does alpha of .01 mean? what does p < 0.01 mean? Using Excel to complete t-tests

  6. Lab sessions Labs continuethis week

  7. Lab sessions Labs continuethis week

  8. Lab sessions Labs continuethis week

  9. No homework due November 2ndJust work on designing and completing your original research project using t-tests (“Project 2” in Labs)

  10. Homework review

  11. . Homework

  12. . Homework

  13. . Homework Type of instruction Exam score 50 40 2-tail 0.05 CAUTION This is significant with alpha of 0.05 BUT NOT WITH alpha of 0.01 2.66 2.02 38 p = 0.0113 yes The average exam score for those with instruction was 50, while the average exam score for those with no instruction was 40. A t-test was conducted and found that instruction significantly improved exam scores, t(38) = 2.66; p < 0.05

  14. . Homework Type of Staff Travel Expenses 142.5 130.29 2-tail 0.05 1.53679 2.2 11 p = 0.153 no The average expenses for sales staff is 142.5, while the average expenses for the audit staff was 130.29. A t-test was conducted and no significant difference was found, t(11) = 1.54; n.s.

  15. . Homework Location of lot Number of cars 86.24 92.04 2-tail 0.05 -0.88 2.01 51 p = 0.38 no Fun fact: If the observed t is less than one it will never be significant The average number of cars in the Ocean Drive Lot was 86.24, while the average number of cars in Rio Rancho Lot was 92.04. A t-test was conducted and no significant difference between the number of cars parked in these two lots, t(51) = -.88; n.s.

  16. . Please hand in your homework – they must be stapled

  17. . Rejecting the null hypothesis Difference between means Variability of curve(s) • If the observed stat is more extreme than the critical stat in the curve: • then it is so rare, (taking into account the variability) we conclude it must be from some other distribution • decision considers effect size and variability • then we reject the null hypothesis – we have a significant result • then we have support for our alternative hypothesis • p < 0.05 (p < α) • If the observed stat is NOT more extreme than the critical stat in the distribution (curve): • then we know it is a common score (either because the effect size is too small or because the variability is to big) and is likely to be part of this null distribution, • we conclude it must be from this distribution • decision considers effect size and variability – could be overly variable • then we do not reject the null hypothesis • then we do not have support for our alternative hypothesis • p not less than 0.05 (p not less than α) p is n.s. Difference between means Difference between means critical statistic critical statistic Variability of curve(s) (within group variability) Variability of curve(s)

  18. A table of t-test results

  19. If this is less than .05 (or whatever alpha is) it is significant, and we the reject null df = (n1 – 1) + (n2 – 1) = (165 - 1) + (120 -1) = 283

  20. How to report the findings for a t-test Sample size 150 150 One paragraph summary of this study. Describe the IV & DV. Present the two means, which type of test was conducted, and the statistical results. Start summary with two means (based on DV) for two levels of the IV We compared productivity for men and women. The mean productivity level for men was 3.65 and the mean productivity for women was 3.43. A t-test was calculated and there appears to be a significant difference in productivity between the two groups t(298) = 3.64; p < 0.05 Type of test with degrees of freedom Describe type of test (t-test versus anova) with brief overview of results Value of observed statistic p<0.05 = “significant”

  21. A table of t-test results “Mastery-Oriented” t-test (top row) is not significant “Performance-Oriented” t-test (bottom row) is significant

  22. A survey was conducted to see whether men or women superintendents make more money 1. Identify the IV and DV 2. Identify the two means and the observed t score 3. Identify the p value and state whether it is less than .05

  23. A survey was conducted to see whether men or women superintendents make more money Are both p values less than 0.05? 1.37834 E-05 Equals .00001378 4 zeros 6.8917 E-06 Equals .0000068917 5 zeros

  24. A survey was conducted to see whether men or women superintendents make more money A note on scientific notation: “E-05” means move the decimal to the left 5 places E-06” means move the decimal to the left 6 places 1.37834 E-05 Equals .00001378 4 zeros 6.8917 E-06 Equals .0000068917 5 zeros

  25. Writing Assignment Part 1 • A survey was conducted to see whether men or women rate their • “quality of life” as higher (on a scale from 1 – 5). Please identify the following: • Identify the IV and DV • Identify the two means and the observed t score • Identify the p value and state whether it is less than .05 df = 283 Writing Assignment – Part 1: Write a one paragraph summary of the study included in this pink box. Here is a template from another study. Follow this formatting carefully using these new data: The mean test scores for participants who completed the big meal was 24, while the mean sensitivity for participants who completed the small meal was 21. A t-test was completed and there is a significant difference in the auditory sensitivity as a function of the size of the meal, t(16) = 3.93; p < 0.05.

  26. Writing Assignment Part 2 • A survey was conducted to see whether men or women • superintendents make more money • Identify the IV and DV • Identify the two means and the observed t score • Identify the p value and state whether it is less than .05 Write a one paragraph summary of this study using the same formatting style.

  27. A survey was conducted to see whether men or women superintendents make more money. The independent variable is a. nominal level of measurement b. ordinal level of measurement c. interval level of measurement d. ratio level of measurement

  28. A survey was conducted to see whether men or women superintendents make more money. The dependent variable is a. nominal level of measurement b. ordinal level of measurement c. interval level of measurement d. ratio level of measurement

  29. A survey was conducted to see whether men or women superintendents make more money. The independent variable is a. continuous and qualitative b. continuous and quantitative c. discrete and qualitative d. discrete and quantitative

  30. A survey was conducted to see whether men or women superintendents make more money. The dependent variable is a. continuous and qualitative b. continuous and quantitative c. discrete and qualitative d. discrete and quantitative

  31. A survey was conducted to see whether men or women superintendents make more money. This is a a. quasi, between subject design b. quasi, within subject design c. true, between subject design d. true, within subject design

  32. A survey was conducted to see whether men or women superintendents make more money. This is a a. one-tailed test b. two-tailed test c. three-tailed test d. not enough information

  33. A survey was conducted to see whether men or women superintendents make more money. The null hypothesis is a. men make more money b. women make more money c. no difference between amount of money made d. there is a difference between the amount of money made

  34. A survey was conducted to see whether men or women • superintendents make more money. If the null hypothesis was rejected we will conclude that • a. men make more money • b. women make more money • no difference between amount of money made • d. there is a difference between the amount of money made

  35. A survey was conducted to see whether men or women • superintendents make more money. A Type I error would be • a. claiming men make more money, when they don’t • b. claiming women make more money, when they don’t • claiming no difference between amount of money made, when there is a difference • d. claiming there is a difference between the amount of money made, when there is no difference

  36. A survey was conducted to see whether men or women • superintendents make more money. A Type II error would be • a. claiming men make more money, when they don’t • b. claiming women make more money, when they don’t • claiming no difference between amount of money made, when there is a difference • d. claiming there is a difference between the amount of money made, when there is no difference

  37. A t-test was conducted, there were ___ men in the study and ___ women. a. 18; 21 b. 21; 18 c. 19; 19 d. 38; 38 Let’s try one

  38. A t-test was conducted, the observed t was _____ a. 2.02 b. 1.68 c. 5.01 d. 1.37 Let’s try one

  39. A t-test was conducted, the critical t was _____ a. 2.02 b. 1.68 c. 5.01 d. 1.37 Let’s try one

  40. A t-test was conducted, which of the following best describes the results: a. t(21) = 2.02; p < 0.05 b. t(21) = 2.02; n.s. c. t(37) = 5.0; p < 0.05 d. t(37) = 5.0; n.s Let’s try one

  41. A t-test was conducted, with a two tail test was there a significant difference? a. No, because 5.0 is not bigger than 6.89 b. Yes, because 5.0 is bigger than 1.68. c. Yes, because 5.0 is bigger than 1.37 d. Yes, because 5.0 is bigger than 2.02 Let’s try one

  42. Which is true a. p < 0.05 b. p < 0.01 c. p < 0.001 d. All of the above Let’s try one

  43. A survey was conducted to see whether women superintendents make more money than men. This is a a. one-tailed test b. two-tailed test c. three-tailed test d. not enough information Note the change in the problem

  44. A survey was conducted to see whether women superintendents make more money than men. A t-test was conducted, which of the following best describes the results:Note the results were in the unpredicted direction a. reject the null b. do not reject the null c. not enough information Let’s try one

  45. A survey was conducted to see whether women superintendents make more money than men. A t-test was conducted, which of the following best describes the results: Note the results were in the unpredicted direction a. t(21) = 2.02; p < 0.05 b. t(21) = 2.02; n.s. c. t(37) = 5.0; p < 0.05 d. t(37) = 5.0; n.s Let’s try one

  46. Thank you! See you next time!!

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