Kids, Cats and Concepts: Toward a Grand Unified Theory of Thinking

1. Kids, Cats and Concepts: Toward a Grand Unified Theory of Thinking Geoff Norman

2. The Goal • To link research in three domains: • Dual processing models of thinking • Exemplar and prototype models of categorization / concept formation • Expertise and clinical reasoning to a greater understanding of human information processing

3. How I got there • Distant • Studies of clinical problem-solving • Intermediate • Role of experience in clinical reasoning • Recent • Diagnostic errors and “dual processing”

4. A Difficult Diagnostic Task

6. An Easy Diagnostic Task

10. The rule is insufficient for the classification task • But we can do the task quickly, accurately, and effortlessly HOW?

11. The Role of Similarity

12. DUAL PROCESSINGTwo basic strategies • System 1 • Based on holistic similarity to prior examples • “Exemplar theory” (more later) • System 2 • Based on underlying conceptual characteristics • “Causal models”

13. System 2 thinking Playing by the rules

15. Analytic View of Expertise “The matters that set experts apart from beginners are symbolic, inferential, and rooted in experiential knowledge…Experts build up a repertory of working rules of thumb or “heuristics” that, combined with book knowledge, make them expert practitioners.” E. Feigenbaum. The fifth generation: artificial intelligence and Japan's computer challenge to the world. 1983

16. System 1 thinking I’ve seen it before and here it comes again

20. Successful categorization • From 2-D abstract representation • without analysis of features • without language • Successful generalization • To other 2 D abstraction in atypical orientation

21. The Non- Analytic View “We must be prepared to abandon the traditional view that runs from Plato to Piaget and Chomsky that a beginner starts with specific cases and… abstracts and interiorizes more and more sophisticated rules.It might turn out that skill acquisition moves in just the opposite direction; from abstract rules to particular cases.” H.L. Dreyfus, 2002

22. Outline Dual processing Concept formation and categorization Expertise and Clinical Reasoning Applications -- Implications Levels of Processing Perception Transfer Aging and reasoning Intelligence

23. Three Literatures Dual Processing (Thinking) Concept formation (categorization) Medin,Brooks Clinical Reasoning Stanovich, Evans, Kahnemann Norman,Schmidt

24. Dual Processing System 1 Rapid, unconscious, based on concrete similarity, “just” pattern recognition System 2 Slow, logical, conceptual, energy-intensive,

25. Unconscious Implicit Automatic Effortless Rapid Holistic, Old (evolution) Contextualized Conscious Explicit Controlled Effortful Slow Analytic New (evolution) Abstract CHARACTERISTICSSystem 1 System 2

26. System 1 “right inferior prefrontal cortex” Evans, 2008 “Involves hippocampus” Smith & DeCoster, 2000 System 2 “ventral medial prefrontal cortex” Neuroanatomy of System 1,2

27. Neurophysiology of System 1,2 • Glucose dose (vs. Placebo) • Shift of processing strategy toward System 2 (more energy demand) with glucose load (Attraction effect - 17% vs. 47%) (Masicampo & Baumeister, 2008)

28. Mental representations • SYSTEM 1 Abstract concepts Feature list, probability, causal mechanism, process • SYSTEM 2 • ???????

29. Categorization / Concept Formation

30. Exemplar Theory - Medin, Brooks • Categories consist of a collection of prior instances • identification of category membership based on availability of similar instances • Retrieval process is “non-analytic (unaware), hence can result from objectively irrelevant features • Retrieval process is not deliberate, not available to introspection • (Like System 1)

31. Dual Processing in Medicine From Process to Knowledge (Analytical and Experiential)

32. The beginnings - clinical reasoning as a process “Hypothetico-deductive method” (Elstein, Shulman, Sprafka, 1977) Expert (and novice) clinicians generate multiple diagnostic hypotheses early in the encounter then gather data to confirm (usually) these hypotheses

33. Does hypothesis predict accurate solution? Barrows, Neufeld, Norman, 1981

34. Where do hypotheses come from? “Medical experts differed from novices in that they generated better hypotheses…… and we don’t know why!” A. Elstein Dx Error Conference May 31, 2008

35. Expert Physicians and Dual Processing To what extent does the: formal knowledge of medical school vs. experiential knowledge of practice contribute to expertise

36. Schmidt & Norman, 1991 Novice Intermediate Expert Examples Basic Science Mechanisms Clinical Rules System 2 System 1 Basic Science Mechanisms Clinical Rules Basic Science Mechanisms

37. Who do you pick? • Dr. JW completed the specialty exam last year and stood 14th in the country. • Dr. WS completed the specialty exam 6 years ago. At the time, she was in the top 1/3 of all candidates.

38. The Conundrum Why do we prefer the candidate with apparently less “competence” but much more experience? What did she get from 10 years of experience? 10 years of experiences (System 1 knowledge)

39. BUT Every measure of formal (System 2) knowledge decays right after graduation

40. Day and Norcini, 1988

41. Evidence of System 1 in Diagnostic Reasoning

42. Visual Diagnosis and Response Time STUDY • 100 slides in 20 categories • Students, clerks, residents, GPs, Dermatologist • Accuracy and Response Time

43. Accuracy by Educational Level

44. Response time by Educational Level

45. Evidence of Exemplars

46. Effect of Similarity (Allen, Brooks, Norman, 1992) • 24 medical students, 6 conditions Learn Rules Practice rules Train Set A Train Set B (6 x 4) x 5 (6 x 4) x 5 Test (9 / 30)

49. Accuracy by Bias Condition

50. Is it just visual similarity? • If it’s “non-analytic” does it apply to objectively irrelevant features?