We give a categorical treatment, in the spirit of Baez and Fritz, of relative entropy for probability distributions defined on standard Borel spaces. We define a category suitable for reasoning about statistical inference on standard Borel spaces. We define relative entropy as a functor into Lawvere's category and we show convexity, lower semicontinuity and uniqueness.

Besides the work of Hella [1991], few studies exist on the visual behavior and visual needs of operators of powered industrial vehicles. Lift trucks, as an example, serve a useful purpose in industry but are also involved in occupational injuries and deaths. An analysis of work inspectors' reports [CSST 2005] from 1974 to 2004 identified 84 cases where the accident was fatal either for the lift truck operator or a co-worker. In 28 of these cases, the lack of visibility offered by the lift truck or due to the load carried, or the visual demands of the operator at the time of the accident, were either cited or presumed factors. Collision and overturning are the main types of fatal accidents. The aim of this paper is to present preliminary results of the use of an eye-tracker to study vision-related issues, and to discuss the feasibility of using such an instrument in field studies.