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A product of cognitive task analysis speaking in a language similar to that of software designers is illustrated through a success story of cognitive systems engineering. This is a method of bridging the gap occurring between intelligent technology and technological interventions.

In 4 experiments, participants alternated between different tasks or performed the same task repeatedly. The tasks for 2 of the experiments required responding to geometric objects in terms of alternative classification rules, and the tasks for the other 2 experiments required solving arithmetic problems in terms of alternative numerical operations. Performance was measured as a function of whether the tasks were familiar or unfamiliar, the rules were simple or complex, and visual cues were present or absent about which tasks should be performed. Task alternation yielded switching-time costs that increased with rule complexity but decreased with task cuing. These factor effects were additive, supporting a model of executive control that has goal-shifting and rule-activation stages for task switching. It appears that rule activation takes more time for switching from familiar to unfamiliar tasks than for switching in the opposite direction.

A theory of executive control is presented that proposes that executive processes control subordinate processes by manipulating their parameters, reconfiguring them to respond in accord with the current task set. It adopts C. Bundesen's (1990) theory of visual attention (TVA) and R. M. Nosofsky and T. J. Palmeri's (1997) exemplar-based random walk (EBRW) as the theory of subordinate processes. It assumes that a task set is a set of TVA and EBRW parameters sufficient to perform a task and that set switching involves changing those parameters. The theory solves 2 computational problems that emerge in dual-task situations: the binding problem and the serial order problem. It can perform dual tasks in series or in parallel but prefers the serial strategy because it is faster and it solves the binding problem naturally. The theory accounts for concurrence cost, set-switching cost, crosstalk between tasks, and the modulation of crosstalk by task set.

We analyzed age-related slowing in 29 younger (M = 22 years) and 30 older adults (M = 70 years) who performed a conceptual comparison task, a naming task, and a simple reaction time task. Both vocal and manual responses were elicited in all except the naming task. Results did not support the hypothesis that there is greater age-related slowing in comparison tasks than in production tasks. In contrast, we found an interaction between age and response modality in the conceptual comparison task. Response latencies of younger participants were shorter in the manual modality whereas those of older participants were shorter in the vocal modality. In the simple reaction time task manual responses were faster in the two age groups. These findings are discussed in relation to models assuming task-specific slowing factors.

This study examined the degree to which different tasks promote the encoding of the characteristics of a talker's voice in young and older adults, and whether these characteristics encoded in long-term memory facilitate spoken word identification under difficult listening conditions. During the encoding phase, participants were given extensive exposure to the voices of two talkers and performed tasks that focused their attention on either voice characteristics (explicitly or incidentally) or linguistic information. Subsequently, participants identified novel words masked by noise, half of which were spoken by one of the familiar talkers and half by an unfamiliar talker. Young adults identified with greater accuracy words spoken in a familiar voice, whereas older adults benefited from voice familiarity only under instructions that promoted attention to voice characteristics either explicitly or incidentally. Age-related declines in sensory uptake (hearing loss) accounted for most of these task-dependent voice effects.

A relatively neglected topic in manual materials handling (MMH) research is the impact of the accuracy of task parameter measurements on the application of various assessment methods. A laboratory experiment was conducted to investigate the accuracy of NIOSH equation parameter measurements made by eight subjects following a 4-h training session. Five individual tasks were measured; two were single tasks and three were part of a multiple-component simulated palletizing operation. Significant differences between reference parameter measurements and average measurements made by subjects were found. The sensitivity analysis showed that frequency and horizontal location are the most important parameters. These parameters also tended to have the highest measurement errors. Recommendations for increasing the effectiveness of training programs for NIOSH equation users based on the results of the study are presented. [C] 2001 Elsevier Science Ltd. All rights reserved. Keywords: NIOSH equation; Manual materials handling; Measurement accuracy

Evidence suggests that studies employing a wide range of task complexity may best show that measures of delayed knowledge of results, post-KR interval, and intertrial interval produce optimal performance.

Do deeper levels of processing produce equivalent priming effects at all stages of task performance? In Experiment 1, we varied the level of processing factorially across two task stages--target selection and response selection. Each stage required perceptual (e.g., color) or conceptual (e.g., friendliness) processing of stimulus items (i.e., animal names). Negative priming was substantially greater when deeper processing was required at the target selection stage, but it was unaffected by the level of processing at the response selection stage. In contrast, positive priming was greater when deeper processing was required at the response selection stage, but it was unaffected by processing at the target selection stage. In Experiment 2, we generalized this finding using a task in which numeric targets were selected on the basis of their parity. As in Experiment 1, the deeper level of processing at the target selection stage produced a larger negative priming effect. These results illuminate the role of target selection demands in modulating the strength of negative priming.

KENNETH H. DOERR [1] ANTONIO ARREOLA-RISA [2] Three sources of variability in task completion times are identified: the task itself, the worker performing the task, and the environment where the [...]

A study examined the role self-efficacy in a social task, delivering a speech in a college class, and a nonsocial task, answering a mathematics test in a college research methods course. The study investigated the influence of gender, parental modeling, generalized self-efficacy in the task domain, and self-efficacy for the two tasks on the achievement of two types of goals. The analysis also determined if self-efficacy functions on a similar level across task domains. Findings revealed that masculinity or instrumentality facilitated general self-efficacy in both task domains and to the specific self-efficacy for speech delivery.

This study attempts to refine the construct of contextual performance by dividing it into 2 narrower constructs, interpersonal facilitation and job dedication. Supervisors rated 975 U.S. Air Force mechanics on at least 1 of 4 aspects of job performance (different supervisors rated each aspect of performance), and 515 of these mechanics also completed self-report individual difference measures. Correlations between performance ratings and individual difference variables support distinguishing task performance from interpersonal facilitation but not from job dedication. Thus this study suggests the need to redefine task performance to include motivational elements of job dedication. Then task performance would include task proficiency and motivation to perform one's own tasks effectively, and contextual performance would include interpersonal skills, the motivation to maintain good working relationships and help others perform their tasks.

In this study, researchers examined the effect of task engagement and experience on frequency rating accuracy with an objective measure of task frequency. By contrasting findings from the memory literature on frequency estimation with current task analysis practices, these investigators proposed that task performers and respondents with low levels of experience would generate more accurate frequency estimates compared with task observers and respondents with high levels of experience. Participants were randomly assigned to a task engagement condition (performer vs. observer) as well as to an experience condition (low vs. high). In support of the hypotheses, participants in the performer and low-experience conditions demonstrated greater accuracy in their frequency ratings. These findings were illustrated with several different measures of accuracy. Implications for task analysis research and practices are discussed.

This laboratory experiment used real-time observation to examine the relationships among goals, work processes, and quantity and quality outcomes using a simple multipath assembly task. Trained observers were able to reliably and accurately document work processes used to perform the task, supporting the use of real-time observation for documenting microlevel task strategies. Results show that (a) work processes were affected by goal content (quantity vs. quality); (b) goal form (gradually difficult vs. fixed and difficult) did not influence outcomes or processes used; (c) work processes and personal goals completely mediated the prediction of quantity outcomes and partially mediated quality outcomes; (d) process-only goals produced a greater number of process changes than outcome goals but led to poorer performance; and (e) outcome goals had a lagged effect on performance. The implications for goal-setting theory are discussed.

The purpose of this study was to examine whether the effect of the Big Five factor of conscientiousness on task performance was mediated by performance expectancy, performance valence, and goal choice. There were 117 business students who completed 6 subscales of the Personality Research Form (D. N. Jackson, 1987), responded to several self-report measures, and performed a simple arithmetic task. A cognitive process model was tested and supported through I4SREL analyses. The effect of conscientiousness on task performance was mediated by performance expectancy and goal choice. Robust effects for performance valence were not observed in this situation. Theoretical and practical implications were discussed.

Research is presented describing the development of a meta-analysis criteria evaluation methodology for use in the field of policy analytic activities.

Dissociations have often been found between skilled task performance and verbalizable knowledge about those tasks. Four experiments were designed to determine when associations and dissociations occur and how they should be interpreted. The experimental task involved the trial-and-error solution of equations whose form was unknown. Initially, the task was analyzed to determine the knowledge that might be expected of an expert, and different possible mental models that subjects might have were identified. Associations between task performance and verbalizable knowledge (measured by questionnaire) occurred when subjects had a moderate amount of practice of finding precise solutions (Experiment 1). A graphical display format improved performance but did not diminish false beliefs (Experiment 2). Even when the equations matched the cover story exactly, verbalizable knowledge still improved with practice (Experiment 3). When the cover story was discarded, subjects still showed an improvement in overall questionnaire score and had different, yet correct, beliefs at the end of the session (Experiment 4). In contrast to some previous work, these experiments show that verbal knowledge can increase with practice but that learning occurs at a different pace for different measures of performance.

In three experiments subjects performed one of five tasks after an initial study phase. Results showed that performance on conceptually driven retention tasks (those requiring the processing of meaning) was consistently dissociated from that on data-driven tasks (those relying more on analysis of physical features). Performance on conceptually driven tasks of free recall, semantic cued recall, and a task of answering general knowledge questions was enchanced most when target items had been generated rather than read at study (Experiment 1) and when subjects formed mental images of item referents at study (Experiment 3). Conversely, the data driven tasks of word fragment completion and recall using graphemic cues were performed best when subjects read rather than generated items at input (Experiment 1) and when the physical features of study and test times matched in terms of modality (Experiment 2) and typography (Experiment 3). These findings indicate that dissociations among memory tasks are better explained in terms of the degree of overlap between mental operations at study and test than in terms of various memory systems underlying different tasks.

A recent study analyzed 98 students assigned to six tasks and examined the aspects of individual differences and task characteristics to determine whether they could be used as predictors of task scheduling. Also analyzed was whether scheduling influenced job performance. Results indicate that students completed boring tasks earlier, and complex tasks later. Results also demonstrate that students with a high need for achievement finished tasks later. Additionally, results indicate that early task completion generated superior performance, and successful workload and prior performance was related to earlier task completion.

This article examines the concept of practice knowledge and its relationship to the use of various sources of knowledge to perform specific job tasks. The authors sent questionnaires to social workers who had received master's degrees two and seven years previously from two Northwestern U.S. universities, and received responses from 90 for a response rate of 41 percent. The questionnaires solicited information on the use and ratings of various knowledge sources in the respondents' work. The respondents indicated they used various sources in various ways, but the findings show only a weak correspondence between the importance assigned to the sources and how frequently they were used. The authors suggest a need exists to explore how different knowledge sources are synthesized into information applicable to the work setting, and propose that practice knowledge be examined in terms of such a synthesis. They further argue that knowledge synthesis may play a major role in knowledge use and in various problem-solving and decision-making processes outside the human services. (Reprinted by permission of the publisher.)

A survey of 419 participants on 22 teams in eight sports tested three hypotheses on the moderating influences of interdependence between leader behaviors, performance, and satisfaction. Winning coaches of high-interdependence sports demonstrated greater leader-initiating structure than did losing coaches of high-interdependence teams or winning coaches of low-interdependence teams. High-interdependence sports studied include: (1) basketball, (2) ice hockey, (3) football, and (4) volleyball. Low-interdependence sports examined include: (1) swimming, (2) tennis, (3) track, (4) golf, and (5) wrestling. Study results suggest that managers of highly interdependent teams or work groups should address the need to control and coordinate member tasks through direct supervision, formal rules, policies, or procedures.

A total of 411 middle-level managers in three Civil Service occupational groups responded to 111 items of a task inventory using Time Spent and Difficulty rating scales. Factor and item analyses were used to form two homogenous subsets of tasks labeled general administrative (75 items) and supervisory tasks (18 items). Analyses of variance conducted on each item indicated there were few differences between respondents of different demographic subgroups, although there were a sizable number of occupational differences. Sex subgroup differences were primarily due to fewer women than men reporting that they were involved in tasks of a budgetary or financial nature and tasks that involved speaking or interacting with large groups of people outside the organization. Ethnic group differences were due to non-White incumbents more frequently reporting that they did not perform a task than did their White colleagues. (Reprinted by permission of the publisher.)

Most prescriptions for managing workers assume that employees' assignments are linked to their work roles and career paths. With increasing frequency, however, people are being assigned tasks that are not clearly linked to those factors. Typically -- and predictably -- performance levels for these 'secondary' tasks are lower than for 'primary' tasks. This article draws on a group process perspective in suggesting guidelines for managing employees assigned to do secondary tasks. (Reprinted by permission of the publisher.)

The job holders' process for judging overall task importance was analyzed using a policy-capturing approach. Sixty incumbents of four jobs rated their respective tasks on five dimensions (e.g., task difficulty) and on the criterion, overall task importance. The results indicated that incumbents' judgments of importance were primarily reflective of task criticality and difficulty of learning the task. Composites of task importance formed from these two component dimensions were found to be more reliable and convergent with average ratings of overall importance than holistic judgments of importance or judgments of relative time spent. In addition, a Q-mode factor analysis indicated that most incumbents used a linear combination of task criticality and difficulty of learning the task regardless of the job they held, suggesting that a composite of these two measures may be generalizable across jobs. (Reprinted by permission of the publisher.)

A laboratory experiment was conducted to test referent cognitions theory, which integrates distributive and procedural justice. Undergraduates worked on two tasks knowing that performance scores from only one of these would count toward their chances for earning a reward. In the subject-decision conditions, the students selected (prior to knowledge about their performance) which task would count. The experimenter selected the crucial task in the experimenter-decision conditions. Feedback from the task that did not count indicated to subjects in high-referent conditions that they would have won the reward if these scores had counted, whereas subjects in low-referent conditions learned they would have lost no matter which set of scores counted. All subjects 'lost' on the task that counted. Only subjects in the high-referent, experimenter-decision condition subsequently expressed feelings of unfair treatment. The results are discussed in terms of limitations to equity theory. (Reprinted by permission of the publisher.)

A study of the relationship between the extent of use of information technology and task characteristics of two jobs using the Job Diagnostic Survey reveals results that parallel past research. The amount of use is positively correlated with variety of skill, feedback from agents, and dealing with other people among clerks. No correlation was found, however, between extent of use and task identity, task importance, and response from the job.

Human Error Identification techniques have been used to predict human error in high risk environments despite the lack of evidence for their efficacy. These techniques are increasingly applied to industrial processes to include product assessment. Analysis showed that human error identification techniques may be acquired easily and have the ability to provide reasonable error predictions.

Three case studies of Cognitive Task Analysis (CTA) for defining systems design and training requirements are described. A critical decision method form of CTA was utilized to extract information from expert white-water rafting guides and general aviation pilots and emergency ambulance dispatchers. In turn, the information obtained was used to develop multi-media tools for training rafting guides and general aviation pilots. Results indicated the utility of the approach to CTA that is based on relevant theory.

The notation and computer-based tool for the Sub-Goal Template task-analytic approach to specifying information requirements were described. Two experiments were conducted in which two notations for redescribing sequences that involve making a choice between task alternatives were compared. Results showed that the computer environment was found to be easier to use and led to more accurate plan redescription. Ergonomic design in developing notations and tools to support task analysis methods were found to be necessary.

Semi-synchronized activity as an aspect of collaboration was described as a challenge for the task analysis of collaborative work. A number of case studies were analyzed to show the relationship between awareness and synchronization in collaborative work. They illustrated that an analysis of collaborative activity requires a consideration of various factors such as activities constituting work, access to these activities, environment where the activities are carried out and constraints that apply to the accessibility and participation in these environments.

A combinatorial model of the multiple-task principal-agent problem is presented.