College-student subjects engaged in judgments of numerosity received stimulus arrays on a computer screen that varied in their number level (low, medium, and high), the speed with which the array developed (slow, medium, or fast), and the density of the items in the array (low or high density). The subjects overestimated number when the array was small (75-125 items) but significantly underestimated number when it was at a medium (150-250) or high level (550-650). Density of array items was a significant variable, since subjects showed more underestimation under the high-density condition. Additionally, there was a speed x density interaction. The results are discussed with respect to which class of variable, sensory or cognitive, most influences perceived numerosity. Although they deal with the animal literature, Davis and Perusse (1988), in their excellent review, distinguish among a number of approaches to the measurement of numerical competence. One of the approaches, estimation, is different from subititing because the subject is re

College students actively felt complex objects for 3 sec, and, after delay intervals of 5, 15, 30, or 45 sec, they received either the same object or a different object for comparison. In a signal detection framework, it was observed that d' scores were significantly higher for the 5-and 15sec intervals than for the 30-and 45-sec intervals. Although a clearly negatively accelerated function was not obtained, this is one of the rare instances in which any decay function has been observed for haptic memory. Although it seems counterintuitive that the entire short-term-memory decay function occupies the narrow band extending from 15 to 30 sec, it is clear from previous studies that short-term haptic memory is unique. Results were discussed in terms of findings in both active-and passive-touch experiments.Invited speakers will include Graham Hitch, Asher Koriat, Michael Pressley, and Wolfgang Schneider. The workshop program will include oral presentations, guest speakers, and poster presentations.The registration fee is 80,000 Italian Liras for participants and 40,000 Italian Liras for students. Payment of the fee should be addressed to PSY.CO 41554/0 Cassa di Risparmio di Trieste, Sede Centrale, Via Cassa di Risparmio 10, 34100 Trieste.