Differential development of 24-h retention capacities for two components of T-maze escape learning by infant mice

At 9 or 11 days of age, separate groups of Swiss-Webster mice received 12, 24, or 40 training trials to the goal opposite their first-trial choice in a shock-escape T-maze task. All groups were retested to the same goal for 25 trials 24 h following training, while maturation controls without prior exposure were trained to the goal opposite their first choice. All groups demonstrated increased escape proficiency during original training on two separate escape components: reaching the choice point and making the correct turn at the choice point. During retention testing, all groups at both ages exhibited better escape performance in terms of reaching the choice point than their maturation controls. However, when escape was measured in terms of choice, none of the groups trained at 9 days of age differed significantly from maturation controls when retested at 10 days of age. In contrast, retention of correct choice point turn varied directly with number of original training trials for mice trained at 11 days of age.     

Instrumental escape learning in the rat at 24-hour intertriai interval: Effects of magnitude and schedule of reinforcement

Three experiments investigated the effects of magnitude and schedule of reinforcement and level of training in instrumental escape learning at a 24-h intertriai interval. In Experiment I, two magnitudes of reinforcement were factorially combined with two schedules of reinforcement (CRF and PRF). Under PRF, large reward produced greater resistance to extinction than did small reward, while the reverse was true under CRF. In Experiment II, two levels of acquisition training were factorially combined with three schedules of reinforcement (CRF, single-alternation, and nonalternated PRF). Patterned running was observed late in acquisition in the single-alternation extended-training condition. Resistance to extinction was greater for the nonalternated PRF condition than for the single-alternation condition following extended acquisition, and the reverse was true following limited acquisition. Experiment III confirmed the extinction findings of Experiment II. The results of all three experiments supported an analysis of escape learning at spaced trials in terms of Capaldi’s (1967) sequential theory.     

Three types of conduct‐problem boys in an educational setting

Third grade boys identified as being disruptive to on‐going classroom activities were grouped according to their teacher's ratings of their behaviour characteristics as unco‐operative (Type I), easily flustered (Type II), and unco‐operative and easily flustered (Type III). No significant differences in performance existed between types on individually administered tests of perception and psycholinguistic abilities. On group administered tests of academic achievement and intelligence, the uncooperative boys did significantly better than the other two types. It was also determined that the easily flustered boys did substantially better on individually administered measures of IQ. than they did on group administered measures. These findings suggest that teachers should avoid using group tests to evaluate disruptive boys they perceive as being easily flustered.     

The evaluation from the program director's viewpoint

In considering the evaluation of the preceptorship and residency programs, our faculty were asked to react to specific dimensions and aspects of the studies. Viewpoints about these data were submitted in formal critiques which will be summarized only briefly here. A number of the comments were in response to specific questions which had been posed; other were spontaneous from the faculty.     

Variation in class size,the class size paradox,and some consequences for students

Even where a total allocation of resources is fixed, it is often possible to vary the distribution of the given resources. This distribution can have important, if sometimes hidden, consequences. In the case of universities, considering the mean class size as given, three nonobvious consequences of the amount of variation in class size are examined. (1) The average class size experienced by students is directly related to the amount of variation in class size. (2) Overall student attendance is inversely related to the amount of variation in class size. (3) Overall student participation time is directly related to the amount of variation in class size. The logic of these relationships is explored, and data on 49 departments and interdisciplinary programs at one university are used to illustrate the nature and extent of the class size paradox at one university.