Goals and Learning in Microworlds

We explored the consequences for learning through interaction with an educational microworld called Electric Field Hockey (EFH). Like many microworlds, EFH is intended to help students develop a qualitative understanding of the target domain, in this case, the physics of electrical interactions. Through the development and use of a computer model that learns to play EFH, we analyzed the knowledge the model acquired as it applied the game-oriented strategies we observed physics students using. Through learning-by-doing on the standard sequence of tasks, the model substantially improved its EFH playing ability; however, it did so without acquiring any new qualitative physics knowledge. This surprising result led to an experiment that compared students' use of EFH with standard-goal tasks against two alternative instructional conditions, specific-path and no-goal, each justified from a different learning theory. Students in the standard-goal condition learned less qualitative physics than did those in the two alternative conditions, which was consistent with the model. The implication for instructional practice is that careful selection and analysis of the tasks that frame microworld use is essential if these programs are to lead to the learning outcomes imagined for them. Theoretically, these results suggest a new interpretation for numerous empirical findings on the effectiveness of no-goal instructional tasks. The standing “reduced cognitive load” interpretation is contradicted by the success of the specific-path condition, and we offer an alternative knowledge-dependent interpretation.     

Reviews: Books and Films

INFINITE GRACE: WHEN THE WORDS OF SCIENCE AND SPIRITUAL HEALING MEET. By Diane Goldner. 346 pp. Hampton Roads, VA: Hampton Roads Publishing, 1999, $23.95. DEATH ANXIETY AND CLINICAL PRACTICE. By Robert Langs. 250 pp. London: Karnac Books, 1997. $33. THE FORCE OF CHARACTER AND THE LASTING LIFE. By James Hillman. 236 pp. New York: Ballantine Books, 1999. $14. THE DEAD MOTHER: THE WORK OF ANDRE GREEN. Edited by Gregorio Kohon. 228 pp. London and New York: Routledge, 2000. $. A DARWINIAN LEFT: POLITICS, EVOLUTION AND COOPERATION. By Peter Singer. 70 pp. New Haven: Yale University Press, 2000. Hardback $. THE ECSTATIC IMAGINATION: PSYCHEDELIC EXPERIENCES AND THE PSYCHOANALYSIS OF SELF-ACTUALIZATION. By Dan Merkur. 226 pp. Albany, New York: State University of New York Press, 1998. $19.95. THE UNKNOWN GOD: SEARCHING FOR SPIRITUAL FULFILLMENT. By Alister McGrath. 123 pp. Grand Rapids: Wm. B. Eerdmans, 1999. $18.00. Films: Crouching Tiger, Hidden Dragon; Girlfight; Gladiator; The Contender     

Trafficking women: Gendered impacts of Canadian immigration policies

Women and men are subject to different forms of human trafficking; sexual exploitation is more common for women than for men, and the purposes of trafficking follow gender roles. This article argues that Canadian immigration policies have differential and discriminatory impacts according to gender. We define human trafficking before critiquing two Canadian immigration programs that leave women vulnerable to exploitation. Interviews, questionnaires, and a review of official documents were employed in exploring the government's response to this phenomenon. Our findings suggest that given the nature of the international trafficking and exploitation of women in Canada, the government's focus on border control is ineffective in protecting trafficked women's human rights and the rights of migrants generally.     

6-羟基多巴胺所致旋转行为的动物模型

选用神经毒素(6-OHDA)造成动物大脑黑质纹状体的单侧性损伤,致使动物的大脑两半球机能显示不对称性。致伤后以可卡因诱发动物的旋转行为。 本实验共观察了成年的Holtzman种系雌性大白鼠43只。结果表明,有38例(88.37％)的多巴胺的耗竭率在85一100％,它们的伤情较为理想。但是,3只动物(6.98％)的多巴胺的耗竭率小于60％,2只动物(4.65％)的多巴胺的耗竭率在60—84％。 本文详细地介绍了如何制备和利用旋转仪自动记录动物的旋转行为,以及用高效液相色谱法测定大脑纹状体内多巴胺的含量。     

EXPERIENCE AND THE WATER-LEVEL TASK REVISITED:

Abstract— A recently published study (Hecht & Proffitt, 1995) reported that adults in Munich, Germany, whose occupations involved considerable experience with liquids in containers, were less accurate on Piaget's water-level task than were comparable adults in other occupations. The present study attempted to replicate that experiment with a North American sample, but using lighter controls. The resulting data and conclusions contrast with those of the original study and indicate instead, that individuals in occupations that provide much experience with liquids in containers (bartenders, waiters and waitresses) are, in fact, more accurate on two versions of the water level task than individuals of equivalent gender, age, and education in control occupations (salespeople, clerical worker). The data are discussed in terms of both the impact and the limit s of experience on spatial-task performance.     

Effects of Alprazolam on Complex Human Functioning1

Benzodiazepines can reduce anxiety, can have favorable effects upon sleep, and may diminish problems that interfere with patients' quality of life. On the other hand, these drugs can generate transient anterograde amnesia and may diminish aspects of task performance. Research on the impact of alprazolam and other “tranquilizing” drugs has generally focused on tasks that remain below the complex efforts of managerial or professional personnel. Alprazolam-induced reduction of anxiety under challenging conditions might aid complex task performance, yet anterograde amnesia might interfere. In the present research, managers participated in validated complex simulation tasks. In a double-blind, dual crossover design, placebo, 0.5 mg, or 1.0 mg alprazolam was administered on 2 occasions during the task day. Drug treatment diminished performance on measures that require sequential actions but improved performance on measures less subject to short term memory but more determined by long-term style of functioning. Thus, depending on task requirements, positive or negative alteration of performance might occur.