1 / 30

The success of ‘success’ in cue search

The success of ‘success’ in cue search. Tim Rakow University of Essex Ben Newell, Nicola Weston & David Shanks ELSE at University College London. The Take-The-Best Heuristic (TTB). Validity determines the search rule for TTB (Gigerenzer & Goldstein, 1996, 1999)

aya
Download Presentation

The success of ‘success’ in cue search

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. The success of ‘success’ in cue search Tim Rakow University of Essex Ben Newell, Nicola Weston & David Shanks ELSE at University College London

  2. The Take-The-Best Heuristic (TTB) • Validitydetermines the search rule for TTB (Gigerenzer & Goldstein, 1996, 1999) • search through cues in descending order of validity • stop search with the first cue that discriminates • choose the object this (single) cue points to • This strategy is surprisingly accurate! • G & G propose that TTB is psychologically plausible

  3. TTB - two potential challenges • Learning? • How easy is it to learn and to access a hierarchy of cue validities? • Efficiency? • Would you always examine a highly valid cue if it hardly ever discriminated?

  4. Using cues for inference • Cue validity- the likelihood of a correct choice given the cue points to one option. • Cue discrimination rate- the likelihood that a cue points to one object • Cue success - the likelihood of a correct choice if only that cue is used (When all possible pairs of objects are considered)

  5. Pros and Cons • A cue with high validity (v) may be ‘unhelpful’ IF its discrimination rate (d) is low • Success(s) reflects both validity and DR: s = d*v + (1 - d)*0.5 Proportion correct from occasions when the cue discriminates Proportion correct from occasions when the cue doesn’t discriminate (and you are forced to guess)

  6. Some experiments In a task environment: • With an objective outcome criterion • Where accuracy is important • But information search has some cost • Which order will best describe people’s search through cues? Descending order of: • Validity (as specified by TTB) • Discrimination Rate (DR) • Success

  7. The share prediction task

  8. Experiment 1: Structure (N = 20) 64 learning trials All information free 128 test trials Costs 1p to obtain a pair of cue values Earn 6p for a correct choice Post-test rating ‘Usefulness’ of each cue

  9. Experiment 1: Task environment Set odds for each cue, combine using Bayes Theorem Fix proportion of ‘yes’ values for each cue Follows from validity & DR Outcome on each trial determined (randomly) according to the cue pattern and the programmed odds for each cue

  10. Experiment 1: Competing hypotheses First cue (Acquired most) Last cue (Acquired least)

  11. Experiment 1: Results

  12. Experiment 1: Findings • It looks like • Success is driving the search through cues • But • Are people learning different cue dimensions? (validity, DR, success?) • Or, only a single cue weight?

  13. Experiment 2: Structure (N = 24) 64 learning trials First test block: 128 test trials Post-test ratings ‘Usefulness’, validity, DR, success (rank) Validities equal group v = .72 for all 4 cues 2nd test block: 64 trials DR equal group d = .50 for all 4 cues 2nd test block: 64 trials

  14. Experiment 2: First Test Block

  15. Estimates of Validity

  16. Estimates of Discrimination Rate

  17. Ranking of cues by success

  18. Any effect of changing the environment? DRs equal group can now focus solely on validity Validities equal group can now focus solely on DR

  19. Experiment 2: Findings • It still looks like • Success is driving the search through cues • Some ability to identify different cue dimensions (DR & validity/success?) • This ability also seen in other experiments (Rakow, Hinvest, Jackson, & Palmer) • Limited adaptation in search in relation to these (partially dissociated) features

  20. Learning & Efficiency • Validity is hard to learn (when DRs vary) • It’s a conditional probability • Can’t simply compare frequencies of correct choices • Need to encode relative frequencies • Search behaviour does reflect both validity and discrimination • Search order better described by success-order than by validity alone or by DR alone

  21. The adaptivity of success-based searchA rational analysis • In a like-for-like comparison of validity-directed search, success-directed search, and DR-directed search, we compared 3 one-reason decision strategies: TTB (Take The Best) STS (Select The Successful) DTD (Draw The Discriminator)

  22. Search through cues by validity is more accurate… Unless, something limits the scope of your search Search by Success Search by Validity

  23. More bangs for your buck with success… …when information search is costly Search by Success Search by Validity

  24. Adaptive Decision Making? • As information costs or information constraints vary: • Which search order is best can change • The optimal length of search will vary • Will people adapt accordingly?

  25. Recent Experiment 100 points for a correct choice 4 cost conditions over 4 testing sessions: Cost per cue: 3 points, 10 points, 17 points, 24 points

  26. Expected pay-off as a function of cue cost

  27. Personal reward as a function of personal information costs Reward Cost of information

  28. The effect of varying cue cost

  29. The stopping rule:The effect of cue cost on information purchase

  30. Conclusions When searching through cues prior to choice, people are: • More likely to search by success than by validity • Somewhat able to dissociate validity and DR • Able to adapt to changes in information costs • But adapt by truncating search rather than by adopting a different pattern of cue search

More Related