Multiple perspectives on the concept of conditional probability

Conditional probability is a key to the subjectivist theory of probability; however, it plays a subsidiary role in the usual conception of probability where its counterpart, namely independence is of basic importance. The paper investigates these concepts from various perspectives in order to shed light on their multi-faceted character. We will include the mathematical, philosophical, and educational perspectives. Furthermore, we will inspect conditional probability from the corners of competing ideas and solving strategies. For the comprehension of conditional probability, a wider approach is urgently needed to overcome the well-known problems in learning the concepts, which seem nearly unaffected by teaching

B Physics at the Tevatron

After a five year upgrade period, the Fermilab experiments CDF and DO are taking high quality data in Run II of the Tevatron Collider. We report on the start-up of both detectors and present a selection of first B physics results from the Tevatron. We also compare different B hadron producers such as the Y(4S) with the hadron collider environment and discuss general features of B physics at a hadron collider.Comment: Posting for the archives: Invited review talk to appear in proceedings of "Physics at LHC" Conference held in Prague 200

Lexical information from a minimalist point of view

Simplicity as a methodological orientation applies to linguistic theory just as to any other field of research: ‘Occam’s razor’ is the label for the basic heuristic maxim according to which an adequate analysis must ultimately be reduced to indispensible specifications. In this sense, conceptual economy has been a strict and stimulating guideline in the development of Generative Grammar from the very beginning. Halle’s (1959) argument discarding the level of taxonomic phonemics in order to unify two otherwise separate phonological processes is an early characteristic example; a more general notion is that of an evaluation metric introduced in Chomsky (1957, 1975), which relates the relative simplicity of alternative linguistic descriptions systematically to the quest for explanatory adequacy of the theory underlying the descriptions to be evaluated. Further proposals along these lines include the theory of markedness developed in Chomsky and Halle (1968), Kean (1975, 1981), and others, the notion of underspecification proposed e.g. in Archangeli (1984), Farkas (1990), the concept of default values and related notions. An important step promoting this general orientation was the idea of Principles and Parameters developed in Chomsky (1981, 1986), which reduced the notion of language particular rule systems to universal principles, subject merely to parametrization with restricted options, largely related to properties of particular lexical items. On this account, the notion of a simplicity metric is to be dispensed with, as competing analyses of relevant data are now supposed to be essentially excluded by the restrictive system of principles