Suchergebnisse

The effects of context on perceptual learning were examined in a visual search task involving words from semantically distinct categories. Subjects were trained for a total of 8000 trials in five conditions consisting of a variably mapped (VM) condition, a consistently mapped (CM) condition, and three context conditions in which the consistency of the targets and distractors was dependent on the joint occurrence of specific target/distractor sets. The results of the training phase of the experiment showed that performance in the context conditions improved more than in the VM condition, indicating some benefit of context in the absence of total consistency, but there was less improvement than in the CM condition. After training, the subjects completed 3200 trials in five transfer conditions in which the targets and distractors of the original CM and context conditions were reversed and a new CM condition was added. In the transfer phase of the experiment there was a significant increase in RT (200 ms), indicative of negative transfer, when the CM target and distractor set were reversed. The switching of VM items to CM improved performance (50 ms). Little effect of target/distractor reversal in the cycle conditions implied that context was not used to learn or maintain relationships among specific targets and distractors. The data suggest that in the absence of traditional consistency, context plays an important role in facilitating performance. The results from the training and transfer phases of the experiment are interpreted from a hybrid-connectionist model of human information processing. The importance of contextual information in real-world tasks is discussed.

Analyse der integrierten ländlichen Entwicklungsplanung in Swasiland und Herausarbeitung ihrer in der sozialen und politischen Struktur begründeten Hindernisse, die vor allem darauf zurückzuführen sind, daß die Einflüsse und Aktivitäten der ländlichen Eliten von einem solchen Programm oft negativ berührt werden. Behandelt werden: Ländliche Entwicklungspolitik vor Erlangung der Unabhängigkeit; das Konzept der späteren integrierten ländlichen Entwicklung und die damit verbundenen Probleme; politische Widersprüche und grundsätzliche Entwicklungshemmnisse im ländlichen Bereich. Nach Ansicht des Autors lassen sich viele der für Swasiland festgestellten Probleme, die in der politischen Struktur begründet sind, auch in anderen integrierten ländlichen Entwicklungsprojekten in Afrika wiederfinden. (DÜI-Hlb)