This study investigated the effectiveness of visual training or verbal training on how to use a text-picture processing strategy for learning from computer-based multimedia instructional material. Sixty-nine university students were randomly assigned to the verbal training group (students received text-based instruction for a text-picture…

Describes two demonstration experiments. Outlines a demonstration of the general principle of positive and negative feedback and the influence of time delays in feedback circuits. Elucidates the principle of negative feedback with a model of the iris of the eye. Emphasizes the importance of feedback in biological systems. (CW)