Effects of contextual interference on learning technical sports skills.

The effects of contextual interference on learning skills of volleyball (volley, bump, serve) are influenced by the scheduling of actual practice sessions: the activities can be proposed in a repetitive practice schedule (blocked practice) by continuously repeating the same task (low interference) or in random practice schedules by performing more tasks or variations of one same activity (high interference). High contextual interference, even though causing immediate limited performance, leads to superior performance on retention and transfer tests. Four experimental groups (13 students each) were placed in conditions of random, blocked, serial, and serial with high interference practice for 8 meetings (2 tests and 6 practice). Analysis yielded significant differences among the groups on a transfer test (long transfer) for the serve, so results in this instructional setting are partially in line with those generally found in laboratory experiments.     

Use of Self: A Brief Report

One of the effects of crisis in a family is that the members become fixed in rigid attitudes with strong, narrow limits imposed on the free flow of feelings. A way for the family therapist to free up the members of such a system is to introduce his own affect into the structure. A child may be required to help the therapist gain entry.     

Describing organizations as reinforcer systems: A new use for job satisfaction and employee attitude surveys

Job satisfaction data on managerial personnel were used to illustrate how organizations can be differentiated and described as reinforcer systems. Twenty-seven specific satisfaction scales were regressed on overall job satisfaction, separately for each of five groups of managers from five organizations. For all groups, overall satisfaction was found to be determined mainly by scales concerning challenge of the job and prospects of one's chosen career. Application of decremental stepwise multiple regression procedures to obtain minimum-variable-set equations resulted in different, though overlapping, sets of variables in the equations for the different organizations. These results suggest a way of describing organizations as reinforcer systems, in terms of the specific determinants of overall satisfaction for the organization.     

The effects of different modes of supervision on vigilance behaviour.

Experiment I was run to determine if a closed-circuit television and a one-way window mode of supervision were as effective as the direct physical presence of an experimenter in inducing enhanced levels of signal detection in a Mackworth-type vigilance task. A control condition of complete subject privacy was also examined. The results indicated that both the television and the window conditions had a positive effect on overall performance which was similar to that observed in the experimenter-presence condition; however, the performance decrement over the 90 min vigil was equivalent for the four modes. A second experiment involving the variable of camera position with an addition of a fourth 30 min. period yielded no significant differences between the camera positions, but overall performance in the television condition was again better than in the control condition. This study suggested that performance can be enhanced even without the physical presence of the experimenter.     

Field dependence and physical ability.

Field-dependence scores of professional dancers, highly skilled performers in tennis, soccer, cricket and track and field athletics, medium-ability level players in the same four sports and a group of non-game players were measured using a rod and frame test. Results showed that highly skilled tennis players were significantly more field-dependent than top-class track and field athletes and medium-ability level tennis players.     

Stimulus control in a discrimination based on a distinctive feature

Six pigeons were instrumentally trained to discriminate between two displays that differed only by the presence of a distinctive feature on the positive or food-correlated display. In accordance with previous studies, subjects learned the discrimination and, in the presence of the positive display, directed most of their responses to the distinctive feature, although responses to the common feature were also reinforced. Subsequent generalization tests revealed that on the positive display, both common and distinctive features produced decremental gradients, contradicting Farthing's (1971) statement that the common feature acquires a control function opposite that of the distinctive feature. Procedural differences probably caused the discrepancy in results; within a display, Farthing presented common and distinctive features successively; the present study used simultaneous presentations of common and distinctive stimuli.     

Information processing complexity and leadership status

144 Subjects divided into four-person groups participated in three discussions. In each group, one member (Target subject) was preselected as either being high or low in cognitive complexity. The groups were then assigned to one of three conditions. Under Continuous Reinforcement the Target subject received a reinforcing light cue following each verbalization in the second of three discussions (no light cues used in the first and third discussions). Target subjects under Partial Reinforcement received light cues on a 50% variable ratio reinforcement schedule. Control subjects received no light cues in any session. Target subjects in both experimental groups showed conditioning effects on all dependent measures. While no differences were found between reinforcement conditions, results suggest that abstract subjects are able to make more use of feedback cues than concrete subjects.