Recent research has demonstrated that word learners can determine word-referent mappings by tracking co-occurrences across multiple ambiguous naming events. The current study addresses the mechanisms underlying this capacity to learn words cross-situationally. This replication and extension of Yu and Smith (2007) investigates the factors influencing both successful cross-situational word learning and mis-mappings. Item analysis and error patterns revealed that the co-occurrence structure of the learning environment as well as the context of the testing environment jointly affected learning across observations. Learners (...) also adopted an exclusion strategy, which contributed conjointly with statistical tracking to performance. Implications for our understanding of the processes underlying cross-situational word learning are discussed. (shrink)

It is argued that there can only be a small-finite number of mathematical objects; that these objects range from the very concrete to the very abstract; and that mathematics is essentially not concerned with objects but with concepts. This viewpoint is described as "mentalist" and is upheld over Platonism, intuitionism, and formalism.

Heyman's model, paradoxically, predicts that whereas a maximizing approach to drug choice will prevent escalation of drug use it will never yield complete abstinence. We suggest an alternative model that overcomes this difficulty by focusing on changes in drug tolerance. A small modification allows maximization to predict either abstinence or moderation (e.g., social drinking).

We argue that the goal of natural excellence, discoverable by scientific observation of the species, is appropriately called good, and the proper object of human development and education. That affirmation stands, but we are forced to acknowledge several conceptual difficulties (in the deliberate creation of “natural” excellences, for example, and in cases of plurality of excellences) and a final inability to reconcile human freedom—surely part of the natural excellence of human life—with the need to prevent humans from using that freedom (...) to sacrifice it (through, for instance, drugs, self-indulgence, and emotional enthusiasms). (shrink)

The dominant approach to environmental policy endorsed by conservative and libertarian policy thinkers, so-called “free market environmentalism”, is grounded in the recognition and protection of property rights in environmental resources. Despite this normative commitment to property rights, most self-described FME advocates adopt a utilitarian, welfare-maximization approach to climate change policy, arguing that the costs of mitigation measures could outweigh the costs of climate change itself. Yet even if anthropogenic climate change is decidedly less than catastrophic, human-induced climate change is likely (...) to contribute to environmental changes that violate traditional conceptions of property rights. Viewed globally, the actions of some countries—primarily industrialized nations—are likely to increase environmental harms suffered by other countries—less developed nations that have not made any significant contribution to climate change. It may well be that aggregate human welfare would be maximized in a warmer, wealthier world, or that the gains from climate change will offset environmental losses. Yet such claims, even if demonstrated, would not address the normative concern that the consequences of anthropogenic global warming would infringe upon the rights of people in less-developed nations. As a consequence, this paper calls for a rethinking of FME approaches to climate change policy. (shrink)

First Published in 1999. Routledge is an imprint of Taylor & Francis, an informa company.