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Contextual Multi-Armed Bandit (CMAB) tasks are anovel framework to assess decision making in uncertainenvironments. In a CMAB task, participants are presentedwith multiple options (arms) which are characterized bya number of features (context) related to the reward as-sociated with the arms. By choosing arms repeatedlyand observing the reward, participants can learn aboutthe relation between context and reward and improvetheir decision strategy. We present two studies on howpeople behave in CMAB tasks. Within a stationary en-vironment, we ?nd that participants are best describedby Thompson Sampling-based Gaussian Process mod-els. This decision rule incorporates probability match-ing to the expected outcomes derived from a rationalmodel of the task and it is especially well-adapted tonon-stationary environments. In a dynamic CMAB taskwe again ?nd that participants are best described byprobability matching of Gaussian Process expectations.Our ?ndings imply that behavior previously referred toas \irrational" can actually be seen as a well-adaptedstrategy based on powerful inference algorithms.Keywords: Decision Making, Learning, Exploration-Exploitation, Contextual Multi-Armed Bandits

How do we perceive the predictability of functions? Wederive a rational measure of a function's predictabil-ity based on Gaussian process learning curves. Usingthis measure, we show that the smoothness of a func-tion can be more important to predictability judgmentsthan the variance of additive noise or the number ofsamples. These patterns can be captured well by thelearning curve for Gaussian process regression, which inturn crucially depends on the eigenvalue spectrum ofthe covariance function. Using approximate bounds onthe learning curve, we model participants' predictabil-ity judgments about sampled functions and ?nd thatsmoothness is indeed a better predictor for perceivedpredictability than both the variance and the samplesize. This means that it can sometimes be preferableto learn about noisy but smooth functions instead ofdeterministic complex ones.

As the use of diesel engines in motor vehicles and heavy equipment increases, the need for skilled diesel mechanics will increase. The author describes education and training needs in schools and industry, gives guidelines for trade and technical curricula, and outlines the kinds of training materials to be developed. (MF)

As controlled clinical vocabularies assume an increasing role in modern clinical information systems, so the issue of their quality demands greater attention. In order to meet the resulting stringent criteria for completeness and correctness, a quality assurance system comprising a database of more than 500 rules is being developed and applied to the Read Thesaurus. The authors discuss the requirement to apply quality assurance processes to their dynamic editing database in order to ensure the quality of exported products. Sources of errors include human, hardware, and software factors as well as new rules and transactions. The overall quality strategy includes prevention, detection, and correction of errors. The quality assurance process encompasses simple data specification, internal consistency, inspection procedures and, eventually, field testing. The quality assurance system is driven by a small number of tables and UNIX scripts, with “business rules” declared explicitly as Structured Query Language (SQL) statements. Concurrent authorship, client-server technology, and an initial failure to implement robust transaction control have all provided valuable lessons. The feedback loop for error management needs to be short. [ABSTRACT FROM PUBLISHER]

The Read Thesaurus (Version 3 of the Read Codes) is a controlled medical vocabulary produced during the Clinical Terms Projects with the involvement of over 2,000 health care professionals from all United Kingdom specialties. In addition to allowing the transfer of clinical information in a meaningful way, it supports analysis of this information and provides a basis for the development of shareable medical knowledge bases. The thesaurus includes a comprehensive, dynamic set of over 7,000 gross anatomic concepts richly linked in a network with over 16,000 operative procedures and 40,000 disorders. The representation of anatomic concepts aims to balance the requirements for expressivity, clearness, and simplicity. The underlying directed acyclic graph hierarchy is independent of the alphanumeric code and enables continued refinement and expansion. A template table allows semantic definition, qualification, and linkage of concepts. [ABSTRACT FROM PUBLISHER]