Alan W. Salmoni

Summary knowledge or results for skill acquisition: Beyond Lavery and Schmidt

Abstract Summary KR involves the presentation of KR, usually via a graph of performance over a prescribed set of trials, following the last trial of each set. Some evidence suggests that summary KR produces more perceptual-motor learning than presenting KR on every trial (Lavery 1962; Schmidt, Young, Swinnen and Shapiro 1989). Using a ballistic timing task, experiment 1 was a replication of Schmidt et al. (1989). Four KR summary conditions were employed 1-, 5-, 10-, and 15-trial summary conditions. The results, although not replicating the previous study, provided some support for the idea of an optimal summary length. During block 1 of the transfer (no KR) trials the 5-trial condition produced less error than the other conditions, even though the condition receiving KR on every trial has been most accurate during the acquisition (KR) trials. This ‘summary effect’ (i.e., reversal of the order of conditions from acquisition to transfer/ retention favouring summary conditions during no-KR trials) was investigated further in experiment 2. Besides the 1-, 5-, and 10-trial conditions, a fourth group was added (10/5) which received summary information every 5 trials (a temporal delay equal to the 5-trial condition), but with a summary of 10 trials (an amount of summary information equal to the 10-trial condition). Although a ‘summary effect’ per se was not obtained, the 10/5-trial condition was more accurate than the other groups during the retention phase. These results indicated that the notion of summary KR is a multifactorial phenomenon.

Knowledge of results and perceptual-motor learning☆

Abstract In experiment 1 four KR precision groups (qualitative, 1-, 2-, and 4-digit KR) were given 10 acquisition followed by 10 KR withdrawal trials in a knob turning task. It was found that by the end of acquisition the qualitative, 2- and 4-digit groups produced significantly less errors than the 1-digit group. Experiment 2 was identical to experiment 1 except that the four precision groups were 1-, 2-, 3-, and 4-digit KR and that before trial 1 the performers were told that the response goal was 8 turns and that the KR units referred to the number of turns they were long or short of this goal. There were 36 acquisition and 15 no KR trials. The above changes eliminated the precision effects found in experiment 1, as there were no group differences for acquisition nor retention trials. It was argued that the typical KR methodology of not telling the subjects the KR units or response goal may be confounding. Specifically, this methodology may interact with the independent variable of interest to produce results which are not consistent with response calibration effects.

Human time estimation: Procedural effects

The purpose of this experiment was to investigate the effects of various trial procedures on human time estimation. Four different procedures were used: (1) experimenter-paced intertrial interval/experimenter-paced retention interval, (2) self-paced intertrial interval/experimenterpaced retention interval, (3) experimenter-paced intertrial interval/self-paced retention interval, and (4) self-paced intertrial interval/self-paced retention interval. Auditory time lengths of 1, 4, and 8 sec were estimated by the method of reproduction. Results showed that the two self-paced retention interval conditions produced a typical range effect in that the 1-sec criterion duration was overestimated and the 4- and 8-sec durations were underestimated. In addition, the two homogeneous trial conditions (i.e., procedures 1 and 4 above) produced more accurate time estimation performance than did the two heterogeneous conditions. Variable error increased as the duration of the time to be estimated increased, and subjects were more variable under the two experimenter-paced retention interval conditions than under the two self-paced conditions. We concluded that the self-paced intertrial interval/self-paced retention interval condition seems to be the best procedure to maximize time-estimation performance.

Some intervening and local factors among shift workers in a developing country – Bangladesh

Shift work can be seen as one of the many factors and conditions associated with the health, safety, and wellbeing of industrial workers. Social, cultural and emotional quality also deserves our attention on human aspects of shift work, because it concerns individuals’ physiology, psychology, genetic and family heritage, social and cultural traits, life style, and circadian rhythms. It is more likely to become apparent that intervening and local factors are related with human aspects of shift work that should be carefully considered in order to improve individuals’ performance, tolerance, familiarity with different shift schedule, family and social lives, as well as to control work‐related difficulties. To address this concern, this paper describes some intervening factors involved with human aspects of shift work in the context of a developing country, Bangladesh, with the aim of identifying local factors and situations in making shift work safe, healthier and productive.

The Effects of Different Knowledge of Results Spacing and Summarizing Techniques on the Acquisition of a Ballistic Movement

The present study crossed three knowledge of results summarizing techniques (single-trial KR, summary KR, and average KR) with two spacing conditions (KR on every fifth trial-20%- and KR on every trial-100%). Participants (n = 10 per group) performed 80 acquisition trials of a ballistic movement task involving both a temporal and spatial goal, followed by 30 immediate (10 min) and 30 delayed (2 days) no-KR transfer trials. For the spatial goal, performance was less accurate (absolute constant error) for the 20% spacing condition than the 100% condition during acquisition, but more accurate during delayed transfer. No effects were significant for variable error. For the temporal goal, performance was more accurate for the summary and average conditions than the single-trial KR condition; however, this effect was only present within the 20% spacing condition and only during Block 1 of acquisition. A similar effect held for variable error as well, except that the effect persisted for acquisition and transfer. It was concluded that the spacing of KR is more influential in promoting spatial accuracy than the summarizing of KR.

A Descriptive Analysis of Elite-Level Racquetball

The results of the three experiments provide insight into the time/motion characteristics of racquetball and the physiological responses of elite-level racquetball players during competition. The maximum oxygen uptakes of the male and female athletes tested were relatively low in comparison to those of other elite-level sports, suggesting that aerobic demand, although necessary, is probably not a limiting factor at this level of racquetball play. Racquetball games at the elite level last from 10 to 15 min, and the distance covered by each player during this time is minimal. Even though the rest periods between rallies are from one to two times as long as the work intervals, the work intensity during the rallies is sufficient to produce an average heart rate of between 75 and 95% of maximum throughout most of a game. Although some lactic acid accumulates in the blood, the concentration remains at a steady state during a game (10 to 30% of maximum).

EFFECT OF INTERPOLATED TEMPORAL ACTIVITY ON TEMPORAL SHORT-TERM MEMORY

The purpose of this research was to determine the retroactive interference effects of a single interpolated task (i.e., one temporal duration) on the retention of a criterion duration. This research is of interest because the mnemonic structure of temporal information of different durations is uncertain. Previous research has indicated that there might be a difference in structure for durations of 1 and 4 sec., although the results are inconsistent. Thus, two criterion durations of 1 and 4 sec. and five interpolated durations (i.e., 60%, 80%, 100%, 120%, and 140% of the duration of the criterion) were utilized under the method of reproduction. In addition, subjects were instructed to use either a counting strategy or none (referred to as conscious time estimation) to facilitate the retention of the temporal information. Recall was less variable when using a counting strategy than not and when estimating 1 sec. than 4 sec. However, there was no effect of interpolated activity when comparing performance across different interpolated conditions (no interpolated activity). Apparently, one interpolated duration is not sufficient to produce structural interference with a single criterion duration.

Weber's Law for the Reproduction of Temporal Information

The main purpose of this research was to determine the numeric values of Webers fraction when subjects were required to estimate temporal durations of 1, 3, 5, 7, and 9 sec. under the method of reproduction. The results provided evidence in support of a constant coefficient of proximity for time estimation of approximately 14.5%.

Counting Strategies and Assimilation Effects in Short-Term Retention of Temporal Information

The purpose of the present research was to examine proactive interference in general and assimilation effects (i.e., shifts in constant error caused by prior responses) in particular, when subjects used covert counting to aid their retention of the temporal information. Visually presented durations of 1, 4, and 8 sec. were estimated by 18 subjects under the method of reproduction. Three retention intervals (i.e., immediate, 15, and 30 sec.) and three intertrial intervals (i.e., immediate, 15, and 30 sec.) were employed. Analysis of constant error provided no indication that proactive interference was operating in the retention of temporal information as there was no increase in error across trials, no increase in error for longer retention intervals, and no interaction between trials and retention intervals. Also, there was no change in variable error as the retention intervals lengthened for any temporal duration except for the 4-sec. criterion. Finally, the rate of counting (counting units/sec.) was different across the durations to be remembered. The major conclusion of the present research was that counting greatly facilitates retention of temporal information as compared to retention without such a time-aiding strategy.

Relationship between Psychomotor Functioning and Health Status among Elderly Persons

45 older adults were tested twice per year for three years in a 9 (psychomotor) by 30 (health status, well-being) matrix of variables. That only 84 significant correlations were found suggests no relationship between psychomotor performance and health status.