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Critical Decision Method (Cdm)


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Critical Decision Method (Cdm)

  1. 1. Critical Decision Method (CDM) Peng Hong
  2. 2. What is CDM? <ul><li>Critical Decision Making (CDM) is a retrospective interview method that employs a set of cognitive probes to non-routine incidents that required expert judgment or decision making (Klein, Calderwood, & MacGregor, 1989). </li></ul>
  3. 3. When? <ul><li>CDM is used for eliciting expert knowledge, decision strategies and cues attended to, and system in naturalistic decision making environment (Militello & Lim, 1995). </li></ul>
  4. 4. Importance of knowledge elicitation <ul><li>Why?? </li></ul><ul><ul><li>Improve the overall level of human performance </li></ul></ul><ul><ul><li>Understand how proficient individuals perform the task </li></ul></ul><ul><ul><li>To study general knowledge, specific information and reasoning process of expert </li></ul></ul><ul><li>CDM- derived from a recognition of critical information and prior knowledge. (as described in Recognition-Primed Decision model) </li></ul>
  5. 5. Distinctions from other knowledge elicitation methods <ul><li>Focus on non-routine cases </li></ul><ul><li>Case-based approach </li></ul><ul><li>Cognitive probes </li></ul><ul><li>Semi-structured probing </li></ul>
  6. 6. CDM Interview <ul><li>Basic: </li></ul><ul><ul><li>About two hours </li></ul></ul><ul><ul><li>Two researchers </li></ul></ul><ul><ul><li>Introduction and establish rapport </li></ul></ul><ul><li>Four phases </li></ul><ul><ul><li>Incident identification </li></ul></ul><ul><ul><li>Timeline verification </li></ul></ul><ul><ul><li>Deepening </li></ul></ul><ul><ul><li>“ What If” Queries </li></ul></ul>
  7. 7. The structure of CDM procedure (Crandall, Klein, & Hoffman, 2006)
  8. 8. Step 1: Selecting an incident <ul><li>Select a non-routine, challenging event </li></ul><ul><li>Identify a incident contains cognitive components </li></ul><ul><li>Avoid death or unusual episode </li></ul><ul><li>Obtain unstructured incident account by providing view of the incident </li></ul>
  9. 9. Step 2: Constructing a Timeline <ul><li>Identify key events and segments </li></ul><ul><li>Reconstruct the account in form of a timeline </li></ul><ul><li>Diagramming the timeline </li></ul><ul><li>Establish a shared view of the facts of the case </li></ul>
  10. 10. Example of timeline from an interview: Fireground Commander
  11. 11. Step 3: Deepening <ul><li>Deepen the understanding of the events </li></ul><ul><li>To build a comprehensive, detailed, and contextualized account of the incident </li></ul><ul><li>From the decision maker’s point of view </li></ul><ul><li>Be able to get a detailed, specific picture </li></ul>
  12. 12. Critical Decision Interview Probes (Klein, Calderwood, & MacGregor, 1989) Probe type Probe content
  13. 13. Step 4:“What If” Queries <ul><li>Hypothetical about the incident </li></ul><ul><li>Illuminate expert-novice differences </li></ul><ul><li>Potential vulnerabilities for error </li></ul><ul><li>Training requirements </li></ul>
  14. 14. Boundaries and Limitations <ul><li>Situations where CDM interviews are not feasible </li></ul><ul><ul><li>No real expert </li></ul></ul><ul><ul><li>Unable to generate useful incidents </li></ul></ul>
  15. 15. Applications <ul><li>Knowledge engineering approach for building expert systems </li></ul><ul><li>Evaluating expert systems </li></ul><ul><li>Identifying training requirements </li></ul>
  16. 16. References <ul><li>Crandall, B., Klein, G. A., & Hoffman, R. R. (2006). Working minds : a practitioner's guide to cognitive task analysis London, England: The MIT Press. </li></ul><ul><li>Klein, G. A., Calderwood, R., & MacGregor, D. (1989 ). Critical decision method for eliciting knowledge. IEEE Transactions on Systems, Man and Cybernetics, 19 (3), 462-472 </li></ul><ul><li>Militello, L., & Lim, L. (1995). Patient assessment skills: Assessing early cues of necrotizing enterocolitis. The Journal of Perinatal and Neonatal Nursing, 9 (2), 42-52. </li></ul>