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Ackerman, P. L. (1992). Predicting individual differences in complex skill acquisition: Dynamics of ability determinants. Journal of Applied Psychology, 77, 598-614.

Author of the summary: David Zach Hambrick, 1998, gt8781a@prism.gatech.edu


Ackerman (1992)


The purpose of the project was to investigate dynamic changes in correlations between ability measures and performance on a complex task (i.e., an ATC task). The major predictions of the study were predicated on two skill acquisition frameworks. First, according to Schneider and Shiffrin’s controlled-automatic processing distinction, skill acquisition is governed by the consistency of information processing demands involved in performing a task. Consistency, as Ackerman explains, refers to "a situation in which stimulus and responses are mapped in a manner that allows for complete certainty once the relationships have been learned" (p. 599). Complete consistency allows for the development of automaticity, while tasks with inconsistent task demands require sustained attention. Empirically, automaticity is evidenced by near-zero slopes in functions relating performance and task demands.


Ackerman’s theory of dynamic changes in ability-performance correlations was the second basis for the current study. Briefly, he proposed that, for tasks with consistent information processing demands, skill acquisition occurs in a stage-like progression (ala Fitts and Posner, 1967), and that dynamic changes in ability-performance correlations occur as skill acquisition progresses. During the first stage, the cognitive stage, general intellectual abilities are the most important predictors of performance, and are required to develop strategies for task performance. As such strategies are formed, the learner progresses to the associative stage. The relation between general ability-performance correlations and practice declines linearly, and perceptual speed abilities emerge as the most important predictors of performance. During this phase, relations between stimuli and responses are strengthened. Finally, in the final phase, the autonomous phase, task performance becomes automatized and occurs with little effort.


Complex Tasks


Unlike many simple laboratory tasks, complex real-world tasks often involve a mixture of both consistent and inconsistent information processing demands. Ackerman’s theory predicts that correlations between overall performance on such tasks and general intellectual abilities should remain high throughout practice, and that performance correlations with perceptual speed and psychomotor speed should remain relatively stable. By contrast, ability-performance correlations for consistent task components with motor demands should follow the pattern described above. Consistent task components with minimal motor requirements should produce declining ability-performance correlations for all classes of abilities. What factors are associated with skill acquisition? Ackerman proposes a model in which ability-performance relations change dynamically, but a number of variables mediate ability-performance relations, including consistency, complexity, and motoric demands.


Task and Procedure


An air-traffic controller simulation task was used, and the task for subjects was to ensure that each plane entering their airspace executed a particular flight plan safely. Each trial consisted of three flight plans--arrivals, departures, and overflights—which corresponded to three task sub-components. Arrivals were judged as the most difficult flight plans to process because a precise subjective judgement about heading and altitude changes is required. By contrast, overflights only require monitoring of the planes as they fly through the airspace at cruising altitude.


Ability tests were administered to measure three classes of abilities: spatial, perceptual speed, and psychomotor speed. Self report measures of positive and negative affect, and self-monitoring were also obtained.


Ability-Performance Relations


The composite index of general ability showed stable correlations with overall performance across practice. A finer-grain analysis revealed that correlations of performance with perceptual speed and psychomotor abilities also remained stable, but that performance correlations with spatial ability and reasoning ability increased with practice. Analysis at the sub-component level of performance showed that both arrivals and departures showed increasing correlations with the composite general ability index. This finding is inconsistent with the prediction that performance on consistent tasks (i.e., arrivals) should show decreasing correlations with general abilities. Nevertheless, there was divergence in the spatial ability functions for arrivals and departures, and this was attributable to increasing performance-spatial ability correlations for arrivals. There was also some evidence for divergence for perceptual speed. Performance correlations with perceptual speed for overflights increased linearly, while the function for arrivals was quadratic. Psychomotor correlations increased for both arrivals and departures. This finding is consistent with the idea that psychomotor (and perceptual speed) performance-ability correlations should increase with practice for consistent tasks.


The final analyses concerned information requests, which constituted a consistent component with minimal cognitive demands. As expected, performance correlations with general abilities were initially high, but decreased. All other performance correlations decreased as well, consistent with predictions.


Summary of Ability-Performance Findings


The major predictions can be summarized as follows:


  1. For overall performance, consistently high general ability-performance correlations, and stable correlations with perceptual speed and psychomotor abilities. Ackerman does not specify whether general ability-performance correlations should increase, or whether perceptual speed and psychomotor correlations should be lower than general ability correlations.

  3. For consistent components with motoric requirements, diminishing correlations with general and spatial abilities, and increasing correlations with perceptual speed and psychomotor abilities.

  5. For components with minimal motoric requirements, initially high but diminishing correlations with general ability, and presumably stable correlations with perceptual speed and psychomotor abilities.


Are the results consistent with the major predictions?


  1. The data are consistent with the first prediction. Performance correlations for reasoning and spatial abilities increased with practice, and were stable for perceptual speed and psychomotor abilities.

  3. Evidence for the second prediction concerning consistent components with motoric requirements (i.e., overflights) was less consistent with predictions. Performance correlations with spatial abilities remained stable for overflights and increased for arrivals, but reasoning-performance correlations increased for both. Perceptual speed-performance correlations increased for overflights (as expected), and followed a quadratic form for arrivals. This pattern of correlations is not entirely inconsistent with the second prediction. However, psychomotor-performance correlations increased for both arrivals and overflights, although it should be noted that the trend for arrivals was quadratic and appeared to be descending.

  5. Analyses of information requests are consistent with the third prediction. Performance correlations with all ability measures declined, and were initially high for spatial abilities (although there does appear to be much difference for constituent ability measures in terms of initial correlations).


Additional Questions and Comments


How interrelated were the measures of spatial, reasoning, perceptual speed, and psychomotor abilities? Subjects did not reach asymptote on overall performance. What would ability-performance correlations look like if asymptotic levels of performance were reached?



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