Control-system theory and performance objectives

Behaviorism, the source of the concept of performance objectives, models behavior as an output emitted by an organism. Control theory suggests a different model, in which the stable patterns called behavior are perceptual variables stabilized against disturbances by variations in motor activities. Control theory provides a clear distinction between a learning model and a performance model. Learning is centered around the control of internal variables by means of changes in the organization of performance. Performance is centered around control of perceptual variables, which the experimenter or teacher must learn to share with the subject or student in order to understand what is being performed.     

Grouping strategies, peer influence, and free time as classroom management techniques with first- and third-grade children

This study systematically investigated the effects of different procedures on classroom behaviors ranging from teacher designated seating groups and seating groups based on sociometric data to peer encouragement and free time reinforcers. Subjects were first- and third-grade children in classrooms using a Follow Through program model. Data were taken on the attending behavior of the children in small groups arranged by the teacher. The level of appropriate attending behavior was low and did not increase when the groups were restructured based on sociometric data. The introduction of instructions to the peer groups to help the child with his or her work brought about a major increase in the third-grade subjects' appropriate behavior. Appropriate attending behavior for the first-grade children did not increase to the predetermined acceptable level until a free time period for each peer group was made contingent upon the appropriate behavior of the subject in each group. Frequencies of verbal interactions suggested peer attention has an effect on the appropriateness of peer interactions.     

An audio-tactile display

Several devices have been developed enabling the blind to adapt to digital and visual displays. Most require extensive training and are relatively expensive. The audio-tactile display described in this paper requires very little training and promises to be inexpensive. Prototypes of the display have been developed for a digital stopwatch, a digital clock, and several electronic calculators. Because the device makes use of electrical impulses to communicate with the blind, it also has numerous potential capabilities as a research tool. The device is based on a panel containing columns of braille digits that are made active through a logic circuit interfacing the braille display with a calculator or other device. The subject scans the braille columns and discovers the digits active in each column when a tone is produced simultaneously with the finger contacting the braille digit.     

Referrals to school psychologists: A national survey

School psychologists serving a national, systematic sample of public elementary and secondary schools were surveyed regarding recent referrals. Most referrals were initiated by school staff members (75% of referrals), and the majority occured initially through formal mechanisms (55% of referrals). Most informal requests for assistance or information eventually became, or were thought likely to become, formal referrals. In 92% of cases, the referral agent's initial communication with the psychologist included some designation of what the pupil was doing or not doing that was viewed as problematic. Poor academic performance was of primary concern in 52% of referrals and social/emotional problems in 31%. More boys were referred than girls, and one-half of referrals from the elementary grades involved pupils in grades K-2. Frequency of referral and reason for referral were not independent of pupil's grade or sex. Reason for referral was independent of time of year (October vs. May) and geographical region.     

Hyperphagia resulting from gut denervation in the sea slug, Pleurobranchaea

Previous research suggests that gut distension by ingested bulk plays an important role in the regulation of food intake in gastropod molluscs. The present study tested whether the bilateral stomatogastric nerves which innervate the esophagus and crop in Pleurobranchaea form a neural pathway carrying information about gut distension to the central nervous system. The posterior branches of the paired stomatogastric nerves were surgically exposed and sectioned in seven experimental animals while the nerves were simply exposed and not sectioned in seven sham-operated control animals. In three, subsequent, daily feeding sessions, the experimental subjects consumed a greater amount of food in terms of percentage of body weight than the control subjects. The experimental animals also gained a greater percentage of body weight and later were found to contain much more food within their guts. The results support the hypothesis that stretch receptors which innervate the gut and which have axons in the stomatogastric nerves form an important negative feedback pathway for the control of feeding in the sea slug.