The quantity versus the distribution of teacher behavior

The overall quantity and distribution of teacher interaction are the respective concerns of research on teacher effectiveness and research on teacher expectations. Factors that have kept both these research areas and their applications to teacher education distinct are considered. Limitations of teacher education programs that deal with either the quantity or distribution of teacher behavior are noted. Next, research that examines both indices of teacher behavior is considered. The paper ends with suggestions for how the content and sequencing of teacher education programs could benefit from an integration of quantity and distribution concerns.     

Electromyographic analysis of bow string release in highly skilled archers

A predominant archery coaching tenet holds that the most effective means of releasing the bow string is by relaxation of the finger flexor muscles without activation of finger extensors. To evaluate the validity of this view, EMG patterns of the flexor digitorum superficialis and extensor digitorum muscles of the draw arm were examined using surface EMG electrodes in 15 highly skilled archers as each performed six shots. Each archer displayed consistent EMG patterns from shot-to-shot and two distinct flexor-extensor patterns were exhibited by the sample. The first, characterized by eight of the archers, supported the relaxation principle. For these archers, both flexor and extensor digitorum activity decreased markedly immediately prior to or at arrow release. The second pattern, characteristic of the remaining seven archers, contradicted the coaching tenet. While the flexor digitorum pattern was essentially the same as that described for the first pattern, the extensor digitorum displayed a marked increase in activity just prior to release, indicating that string release was facilitated by an active extension of the fingers. It was concluded that highly skilled archers do not predominantly reflect a release consistent with the coaching canon and that factors other than the string release mechanism discriminate the performances of skilled archers.