1 / 36

NUMERAY & DECISION MAKING

NUMERAY & DECISION MAKING. And why you should have paid more attention to your math teacher…. Santiago Garcia Rodriguez. Numeracy… and the lack thereof! (Paulos, 1998). Ability to deal and understand the fundamental notions of number and chance Is more widespread than we imagine

mariko-ryan
Download Presentation

NUMERAY & DECISION MAKING

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NUMERAY & DECISION MAKING And why you should have paid more attention to your math teacher… Santiago Garcia Rodriguez

  2. Numeracy… and the lack thereof!(Paulos, 1998) • Ability to deal and understand the fundamental notions of number and chance • Is more widespread than we imagine • Has pervasive consequences on people’s decision making processes

  3. Innumeracy is associated with… • Misinformed govt. policies • Susceptibility to pseudoscience • Confused personal decisions • Unawareness of the additivity of small quantities • Strong tendency to personalize

  4. Wait a sec… I need scientific evidence! • High numerates= better medical decision making Hamm, Bard, and Scheid (2003) • Low numerates= less trust in numerical vs. verbal info from physicians Gurmankin, Baron, and Armstrong (2004) • High numerate people are more likely to apply the rules of Expected Value Benjamin and Shapiro (2005) • More educated individuals (more numerate?)= more risk tolerant Donkers, Melenerg, and van Soest (2001)

  5. Framing Effects and Numeracy • Less framing effects among high in quantitative skills (numeracy self-assessed) • Less risky-choice framing within-subjects (numeracy self-assessed) • High NC-High numerates suffered from less risky-choice framing effects (numeracy self-assessed)

  6. Peters, Västfjäll, Slovic, Mertz, Mazzocco, and Dickert (2006) • Less numeracy = stronger attribute framing

  7. Peters, Västfjäll, Slovic, Mertz, Mazzocco, and Dickert (2006) • Probabilistic vs. frequentistic modes of info presentation

  8. Peters, Västfjäll, Slovic, Mertz, Mazzocco, and Dickert (2006) • Less numeray = less optimal choices

  9. Peters, Västfjäll, Slovic, Mertz, Mazzocco, and Dickert (2006) • May high numerates act less rationally?

  10. Peters, Västfjäll, Slovic, Mertz, Mazzocco, and Dickert (2006) • Also found high numerates to draw more precise affective meaning from numbers • Even controlling for intelligence the previous results hold true • We need more studies

  11. Garcia-Rodriguez, Peters, and Slovic (master’s thesis) • Take a step further Peter’s et al. (2006) initial research on framing and numeracy • Investigate the effects of numeracy on risky-choice and attribute framing problems • Find interesting results

  12. Risky-Choice Framing and NumeracyDesign Study 1 • Between subjects design with 2 conditions • N=161, females= 47% • Cond. 1 and Cond. 2 had different frames • 10 “Asian disease”-like problems • Different Expected Value • 4 equal EV • 3 option EV A>B • 3 option EV A<B

  13. Risky-Choice Framing and NumeracyDesign Study 1 Disease Scenario Sweden is preparing for the outbreak of an unusual disease, which is expected to kill 600 people. The following alternative programs have been proposed to limit the spreading of the disease: • If program A is adopted, 200 people will be saved. • If program B is adopted, there is 1/3 probability that 600 people will be saved, and 2/3 probability that no people will be saved.

  14. Risky-Choice Framing and NumeracyAnalyses Study 1 • Averaged the ratings per individual for each subset of problems • Dichotomized numeracy status (low/high) • MANOVA test with the three types of problems as the DV

  15. Results Study 1When EV A=B • Frame main effect F(3,154)=15.04, p<.0001 • Numeracy main effect F(3,154)=4.35, p=.006

  16. Results Study 1When EV A>B • Frame main effect F(1,156)= 21.29, p<.0001

  17. Results Study 1When EV A<B • Numeracy main effect F(1,156)=10.56, p=.005

  18. Attribute Framing and NumeracyDesign Study 2 • Between/within subjects design with 2 conditions • N=161, females= 47% • Cond.1 and Cond. 2 had different frames • Frame was manipulated within subjects • Two types of problems: • Student Evaluation problems • Snack attractiveness ratings

  19. Attribute Framing and NumeracyDesign Study 2 Student Problems Please, rate this student’s performance based on the course level and the % correct on the exam. Snack Attractiveness Problems Please, rate this snack’s attractiveness based on the calories per serving and the % of calories from sugar

  20. Attribute Framing and NumeracyAnalyses Study 2 • Dichotomized numeracy status (low/high) • MANOVA tests separated for students’ and snacks’ tasks, and also frames • MANOVA for • Students 1,3,5 • Students 2, 4 • Snacks A,C,E • Snacks B,D

  21. Results Study 2Students’ Performance Part • Moderate performers: 1st, 3rd, and 5th students • Frame effect: F(3,155)=6.84, p<.0001

  22. Results Study 2Students’ Performance Part • Moderate performers: 1st, 3rd, and 5th students • Frame x Numeracy Int.: F(3,155)=3.18, p=.026

  23. Results Study 2Students’ Performance Part • Extreme performers: 2nd and 4th students • Frame effect: F(2,156)=12.29, p<.0001

  24. Results Study 2Snacks’ Attractiveness Part • Moderate sugar content: snacks A, C, & E • Frame effect: F(3,154)=23.08, p<.0001

  25. Results Study 2Snacks’ Attractiveness Part • Highest sugar content: snacks B & D • Unexpected Int. Frame x Num: F(2,156)=6.03, p=.003

  26. Results Study 2Putting everything together • Frame had an effect except in the evaluation of extreme snacks • Numeracy had an effect in the student performance task, but only with moderate performers • The evaluation of extreme snacks yielded unexpected results!!!

  27. Results Study 2Conclussion • There is a framing effect going on • Low and high numerates behave differently • Frame manipulation might have been weak

  28. Study 3Making the Frame Manipulation Evident • Within/between subjects design • Frame manipulation within subjects • Two groups receiving different frames • N=116, 59% females • Isolated Attribute-Framing problems • Participants informed about the frame manipulation

  29. Study 3The Task Please rate Snack’s X attractiveness based on the information on the screen. Please circle the number that best expresses your feeling on the scale below

  30. Study 3Analyses • Dichotomized numeracy status (High/Low) • MANOVA with the snacks’ ratings as the DV • IV’s: Condition (1st negative/1st positive) and numeracy (high/low)

  31. Study 3Results • Condition main effect: F(4,109)=4.16, p=.004

  32. Study 3Results • Interaction Condition x Num: F(4,109)=3.88, p=.006

  33. Study 3Conclusions • Numeracy seems to affect attribute-framing • Low numerates suffer more from framing • Low numerates are more influenced by wording • High numerates are more influenced by numbers • Interesting: • Reverse frame effect when framing is made clear • But only for low-numerates

  34. Putting Everything Together • Less numeracy = More framing • Stanovich and West (1998), Peters et al. (2006), Garcia-Rodriguez et al (in progress). • Less numeracy = More risk averse • Donkers et al. (2001), Frederick (2005), Peters et al. (2006), Garcia-Rodriguez et al. (in progress) • Less numeracy = Less affect from numbers • Peters et al. (2006)

  35. Future Directions? • Numeracy and: • Risk perception • Affective decision making • Reverse framing effects • Anchoring • Time preferences

  36. Suggested Readings • Benjamin, Daniel and Jesse Shapiro (working paper) “Who is ‘Behavioral’? Cognitive Ability and Anomalous Preferences” • Donkers, Melenberg, and van Soest (2001), “Estimating Risk Attitudes Using Lotteries: A Large Sample Approach”. Journal of Risk and Uncertainty. 22.2 pp. 165-95 • Gurmankin AD, Baron J, Armstrong K. (2004) Intended message versus message received in hypothetical physician risk communications: exploring the gap. Risk Analysis 24:1337-47. • Frederick, Shane. "Cognitive Reflection and Decision Making." Journal of Economic Perspectives 19, no. 4 (2005): 25-42. • Hamm, R.M., Bard, D.E., and Scheid, D.C. Influence of numeracy upon patients' prostate cancer screening outcome probability judgments. Poster at 2003 Judgment and Decision Making Society meetings, Vancouver, BC, November 9 - 10, 2003. • Paulos, J. A. 1988. Innumeracy: Mathematical illiteracy and its consequences. New York: Hill and Wang. • Peters, E., Västfjäll, D., Gärling, T., & Slovic, P. (2006). Affect and decision making: A “hot” topic. Journal of Behavioral Decision Making, 19(2), 79-85. • Peters, E., Västfjäll, D., Slovic, P., Mertz, C.K., Mazzocco, K., & Dickert, S. (2006). Numeracy and decision making. Psychological Science, 17(5), 408-414. • Stanovich, K. E., & West, R. F. (1998a). Individual differences in framing and conjuction effects. Thinking and Reasoning, 4, 289–317. • Stanovich, K. E., &West, R. F. (1998b). Individual differences in rational thought. Journal of Experimental Psychology: General, 127, 161–188.

More Related