Much problem solving and learning research in math and science has focused on formal representations. Recently researchers have documented the use of unschooled strategies for solving daily problems -- informal strategies which can be as effective, and sometimes as sophisticated, as school-taught formalisms. Our research focuses on how formal and informal strategies interact in the process of doing and learning mathematics. We found that combining informal and formal strategies is more effective than single strategies. We provide a theoretical account of (...) this multiple strategy effect and have begun to formulate this theory in an ACT-R computer model. We show why students may reach common impasses in the use of written algebra, and how subsequent or concurrent use of informal strategies leads to better problem-solving performance. Formal strategies facilitate computation because of their abstract and syntactic nature; however, abstraction can lead to nonsensical interpretations and conceptual errors. Reapplying the formal strategy will not repair such errors; switching to an informal one may. We explain the multiple strategy effect as a complementary relationship between the computational efficiency of formal strategies and the sense-making function of informal strategies. (shrink)

This ancient tale has naturally been recognized by modern scholars for what it is—a story of the Great Mother and her paramour; but several features appear to me to have been given less examination than they deserve, in view of their own peculiarity and the obvious antiquity of the myth. That it is pre-Greek is fairly clear from the names of the principal actors. Anchises yields no tolerable meaning in Greek, and we do not know to what speech it belongs—possibly (...) Phrygian. Aphrodite is, of course, no Greek goddess at all. The tale was known to Greek saga-men about the tenth century B.C., and is fully told for the first time, so far as our surviving records go, in a document possibly of the seventh century—the Homeric Hymn to Aphrodite. Connected as it is, though loosely, with the Troy-saga, it may quite possibly go back to Minoan-Mycenaean times, as that does. The features which I think worthy of further investigation are the fate of Anchises after his enjoyment of the goddess' favours, and in particular the effect upon him of the thunderbolt with which he was smitten. (shrink)

L'A. esamina i commentari al De anima di Filopono, dello pseudo-Filopono e dello pseudo-Simplicio.

The author joins the discussion on selection of patients in the face of life-saving resources initiated in the Journal by Parsons and Lock, Mooney and the editorial in the December 1980 issue. In this article several selection systems are discussed. The author is in favour of a `criteria-system'. The criteria for such a system are elaborated. On the basis of a sequence of values a sequence of criteria is proposed. Attention is also given to the procedural aspects.

Among those subjects which have yet to receive general treatment in Scholastic texts is the present one of emotions. Mr. Wirtenberger herein presents a compilation of opinions on this subject.