One of the tasks with which communication engineers are presented is that of devising a mechanism by which a significant sequence of words, a message, produced by somebody, the sender of the message, is reproduced at some other place, with the shortest practical time lag. The reproduction must be such that the receiver of the message will be able to understand what the sender meant by his message, at least, if he knows the sender's language. The following illustration is typical: (...) A writes on a sheet of paper “I love you” and wishes that B, 3000 miles away, should become aware of the full content of this message, with little delay and at a low cost. There will be institutions, in a capitalistic society, which will compete with each other in providing A, for a price, with the required service. Those companies which perform these services most satisfactorily, i.e., with an overall better combination of faithfulness, time lag, and cost, will get the job. The executives of these companies will hire engineers and put them to work on improving this overall combination. (shrink)

Recently, Nathan (1986) criticized Bar-Hillel and Falk's (1982) analysis of some classical probability puzzles on the grounds that they wrongheadedly applied mathematics to the solving of problems suffering from "ambiguous informalities". Nathan's prescription for solving such problems boils down to assuring in advance that they are uniquely and formally soluble--though he says little about how this is to be done. Unfortunately, in real life problems seldom show concern as to whether their naturally occurring formulation is or is not ambiguous, (...) does or does not allow for unique formalization, etc. One step towards dealing with such problems intelligently is to recognize certain common cognitive pitfalls to which solvers seem vulnerable. This is discussed in the context of some examples, along with some empirical results. (shrink)

Subjects were requested to choose between gambles, where the outcome of one gamble depended on a single elementary event, and the other depended on an event compounded of a series of such elementary events. The data supported the hypothesis that the subjective probability of a compound event is systematically biased in the direction of the probability of its components resulting in overestimation of conjunctive events and underestimation of disjunctive events. Studies pertaining to this topic are discussed.

Neste artigo, Bar-Hillel e Carnap apresentam pela primeira vez as ideias básicas de uma teoria da informação semântica. O conceito de informação, baseado em sentença declarativa em uma dada linguagem, é definido pelo conteúdo descritivo expresso pelas sentenças. A quantidade de informação é calculada com base em um conjunto de funções lógicas probabilísticas sobre conjuntos de conteúdos descritíveis. Esta teoria tem aplicabilidade dedutiva e indutiva, significando um marco para o desenvolvimento das teorias filosóficas da informação.

1. Stumpers, as defined here, are riddles so simple that kids can solve and appreciate them – yet so elusive that even intelligent adults can be completely stumped by them. Example: Alex is Bobbie’...