Uncovering the requirements of cognitive work

OBJECTIVE: In this article, the author provides an overview of cognitive analysis methods and how they can be used to inform system analysis and design. BACKGROUND: Human factors has seen a shift toward modeling and support of cognitively intensive work (e.g., military command and control, medical planning and decision making, supervisory control of automated systems). Cognitive task analysis and cognitive work analysis methods extend traditional task analysis techniques to uncover the knowledge and thought processes that underlie performance in cognitively complex settings. METHODS: The author reviews the multidisciplinary roots of cognitive analysis and the variety of cognitive task analysis and cognitive work analysis methods that have emerged. RESULTS: Cognitive analysis methods have been used successfully to guide system design, as well as development of function allocation, team structure, and training, so as to enhance performance and reduce the potential for error. CONCLUSIONS: A comprehensive characterization of cognitive work requires two mutually informing analyses: (a) examination of domain characteristics and constraints that define cognitive requirements and challenges and (b) examination of practitioner knowledge and strategies that underlie both expert and error-vulnerable performance. A variety of specific methods can be adapted to achieve these aims within the pragmatic constraints of particular projects. APPLICATION: Cognitive analysis methods can be used effectively to anticipate cognitive performance problems and specify ways to improve individual and team cognitive performance (be it through new forms of training, user interfaces, or decision aids).     

Using cognitive work analysis and the strategies analysis diagram to understand variability in road user behaviour at intersections

In this article, an application of cognitive work analysis (CWA), using the strategies analysis diagram (SAD) method, to model performance variability in road transport, is presented. Specifically, the method was used to describe performance variability across four road user groups (drivers, cyclists, motorcyclists and pedestrians) when turning right at an urban signalised intersection. The analysis demonstrated that the method was able to identify a comprehensive range of strategies that road users can potentially use while turning right at an intersection, thereby describing a range of performance variability within intersection systems. Furthermore, the method identified constraints, disturbances, changes in circumstances and other influences on road user performance variability. It is concluded that the CWA/SAD approach was able to describe both the different ways in which activities can be executed and disturbances, situations and constraints that create performance variability. The implications of these findings for road design and intersection safety are discussed along with the benefits and drawbacks of the methodology used.

Practitioner Summary: Recently, the strategies analysis diagram was proposed as a method to support the cognitive work analysis framework in modelling performance variability. This article evaluated this method within a complex sociotechnical system, namely road transport. The application provided insight into performance variability across road user groups when turning right at intersections.     

Accounting for memes in sociotechnical systems: extending the abstraction hierarchy to consider cognitive objects

Work domain analysis (WDA) is used to model the functional structure of sociotechnical systems (STS) through the abstraction hierarchy (AH). By identifying objects, processes, functions and measures that support system purposes, WDA reveals constraints within the system. Traditionally, the AH describes system elements at the lowest level of abstraction as physical objects. Multiple analyses of complex systems reveal that many include objects that exist only at a conceptual level. This paper argues that, by extending the AH to include cognitive objects, the analytical power of WDA is extended, and novel areas of application are enabled. Three case studies are used to demonstrate the role that cognitive objects play within STS. It is concluded that cognitive objects are a valid construct that offer a significant enhancement of WDA and enable its application to some of the world’s most pressing problems. Implications for future applications of WDA and the AH are discussed.

Practitioner summary: Some sociotechnical systems include memes as part of their functional structure. Three case studies were used to evaluate the utility of introducing cognitive objects alongside physical ones in work domain analysis, the first phase of cognitive work analysis. Including cognitive objects increases the scope and accuracy of work domain analysis.     

Designing for attention with sound: challenges and extensions to ecological interface design

OBJECTIVE: We explore whether ecological interface design (EID) principles can be applied to the design of an auditory display for anesthesia monitoring. BACKGROUND: EID examples focus almost exclusively on visual displays. In the anesthesia work environment, however, auditory displays may provide better individual and team awareness of patient state. METHOD: Using a work domain analysis of physiological monitoring in anesthesia, we identify information to display. Using the skills, rules, and knowledge distinction we identify cognitive control needed. Using semantic mapping we map physiological variables and constraints to auditory dimensions. RESULTS: EID principles do not address when information should be displayed and to whom. An attentional mapping stage helps to specify answers to these questions so that a workable auditory display for anesthesia monitoring is achieved. CONCLUSION: EID principles of representing work domain functional structure and minimizing resource-demanding cognitive control are necessary but insufficient to specify requirements for an effective auditory display. Also needed are analyses of control tasks, strategies, and the social organization of work. Such analyses are an integral part of the broader cognitive work analysis framework from which EID emerged. APPLICATION: Actual or potential uses of this research include the design of displays that support continuous peripheral awareness in collaborative multimodal work environments.     

Bridging the gap between analysis and design: improving existing driver interfaces with tools from the framework of cognitive work analysis

Two studies of train driving are presented, both within the framework of cognitive work analysis. In the first study, the modelling tool abstraction–decomposition space is adapted to routine conditions, making the analysis more representative for normal procedures. A major contribution to these analyses was the use of the method for ‘collegial verbalisation’. One particular advantage with this method over other verbalisation methods is that it supplies the analysts with data that contain much more information, but not at the expense of being more subjective. On the contrary, this method produces think-aloud protocols from video-recordings that do not have to be interpreted by the researcher. From these analyses, it was possible to distinguish information that is an intrinsic part of the train driver task from information that is dependent on the configuration and design of the current support system. The analyses show that the driver works in three rather separate time intervals with a long-range, a short-term and an immediate sense of perspective. The driver switches between these while travelling between two stations. Based on these behaviour-shaping constraints, a prototype of a planning area of a driver interface was developed, making feed-forward planning possible for the driver. Four design iterations were completed, using a user-centred system design (UCSD) approach. Early tests show that the planning area of the interface supports the feed-forward decision strategy used by drivers who prefer an active driving style. However, the driver group also made substantial changes in the design, indicating that UCSD is an efficient tool in order to capture user competencies, and to bridge the gap between analysis and design.     

Implicit shift scheduling with multiple breaks and work stretch duration restrictions

This paper considers a shift scheduling problem that includes different forms of flexibility in terms of shift starting times, break lengths and break placement. Two particular forms are studied: fractionable breaks and work stretch duration restrictions. Unlike standard breaks, fractionable breaks are not required to be attributed as a whole. They can be divided into fractions of breaks under some conditions. The distribution of breaks within a shift is done with respect to work stretch duration restrictions to ensure a correct mix of periods of work and rest. Two implicit models are proposed. They extend previous work on implicit modeling of break placement to incorporate the concepts of fractionable breaks and work stretch duration restrictions. In this context, we show the merits of using the so-called forward and backward constraints to model work stretch duration restrictions. We also introduce a new formulation of the forward and backward constraints and demonstrate that it considerably reduces the density of the constraint matrix of the two proposed models. Finally, we study the impact of fractionable breaks and work stretch duration restrictions and show that, for some instances, the use of these concepts considerably reduces the workforce size when compared to other traditional approaches.     

Integrating cognitive and collective aspects of work in evaluating technology

Ergonomic criteria are receiving increasing attention from designers but their applications do not ensure that technology matches the user's abilities, needs, and work constraints. In this paper, we used two series of studies conducted in the healthcare system to illustrate how important work analysis is in evaluating new technology in order to identify critical dimensions of work and anticipate the impact of the devices on these dimensions: one looking at a new automatic drug device for anesthetists and one at a new robotic surgery system. Given the results, we developed a methodology for evaluation of new technology in complex systems. The aim is to insist to assess the impacts of technology on all the dimensions of work: technical, performance, cognitive, organizational, and economic. Which dimensions and criteria will be developed more in detail depends on the results of the work analysis.     

Analyses of activity design in geometry in the light of student actions

Abstract

The goal of this study is to show that inquiry activities in a dynamic geometry environment, intentionally designed to confront students with contradictions and uncertainties, push them towards explanations that include deductive elements. Three different but dependent aspects of the activities are characterized and analysed: The epistemological, which includes all possible inquiry paths; the didactic, which involves only those paths that reflect the intention of the designer; and the cognitive, which accounts for actual student actions (conjectures and explanations) and their analyses. The research conclusions are based on the interplay among these three aspects. The analysis of students’ investigations and the analysis of their explanations fulfil, to a broad extent, the design goals.     

失重环境下可控柔性臂的模态特性

在非重力场中,考虑控制器动态反馈的影响,对存在控制器定位约束的柔性臂系统进行动力分析,研 究其在相对平衡位置的模态特性．以具有柔性关节和弹性臂杆的可控柔性臂为研究对象,分析了控制器作用下的反 馈约束特性,将控制器位置和速度增益引入力边界条件,得到了耦合控制器参量的模态特征方程,证明了反馈约束 的存在使得系统特征频率为复频率,且模态主振型是复变函数．通过数值仿真,明确了可控柔性臂的模态特性与控 制器增益之间的关系,得到了不同于经典振动理论的结论．设计了可控柔性臂的仿失重实验平台,试验模态结果证 明了理论分析的有效性．     

The impact of policy measures on promoting the modal shift from road to rail

This paper aims to examine the impact of policy measures on promoting a modal shift. Based on the results put forth by previous research, we first formulate hypotheses that describe the effects between policy measures and modal shift. Using these hypotheses, we set up the research framework to complete this study, which is then tested with data (sample size 171) and AMOS 18.0. The paper contributes to the literature in the following ways: First, we verify this impact with statistical analyses through testing hypotheses based on the previous research. Second, we develop the model describing the effects between policy measures and clarify their directivity with structural equation modeling. The directivity of effects accounts for the interaction and relationship between policy measures to promote a modal shift. In this paper, we clear up the effects of policy measures better in order to promote a modal shift, which the previous research discussed conceptually.     

Do we want to keep working in 12-h shifts? The follow-up of the work schedule change in a Portuguese industrial company

BackgroundIn Europe, atypical work schedules assume an increasing position, framed by the so-called “adaptability regime”. Despite being seen as a “temporary” option, this regime supports the extension of the working hours up to 12 h per shift.ObjectiveThe purpose of this study was to analyse how the workers from a Portuguese industrial company perceive the impacts of a 12-h schedule, after replacing the former 8-h shift schedule.MethodsThe sample included a total of 87 shiftworkers of an industrial company. A mixed method research was followed based on the ergonomic work analysis, using observations; a self-report instrument describing a week working on 2 × 12 h; and a questionnaire.ResultsField study findings are consistent in showing that, in 2 × 12 h, the workers perceive the risks as resized, both physical risk factors (e.g., noise) and factors related to the work organization (e.g., work pace). The results also reveal a perceived aggravation of the main health outcomes: “sleep debt”, feeling of chronic fatigue, and muscles pains. Despite this, most workers prefer the new 12-h schedule, but not until their retirement age.ConclusionAt present, it is noticed that the new schedule receives collective acceptance and is considered the least-worst option; the advantages outside work seem to compensate the higher costs imposed by this schedule.Relevance to industryOur findings highlight ergonomics' contribution to the sustainability of the work in 12-h shifts, establishing the conditions that enable a technical-scientific opinion supporting the company's decision on the exposure length of the workers to these work schedules.     

Identifying competences for the design of systems supporting complex decision-making tasks: a managerial planning application

The work presented in this paper is addressed to the front-end phases of the development of a system supporting a complex decision-making task: high-level managerial planning in small-to-medium enterprises (SMEs). It attempts to identify characteristics of the competences possessed by experienced managers and used when taking high-level managerial planning decisions, and to assess their potential implications for system design. The work is based on the assumption that the design of effective systems supporting complex decision-making tasks in a specific domain, would require elicitation of competences possessed by experienced persons in the domain, especially those related to the mental processes followed when confronting the cognitive constraints involved in the specific decision-making environment. Such an investigation would lead to the development of systems improving decision making since they would (1) respond to the difficulties met by potential users in performing complex decision-making tasks; (2) reduce possible negative consequences of users' decision-making competences; and (3) at the same time they would achieve the required compatibility with users' mental processes. The research methodology was based on a planning scenario and on an analysis of verbal protocols obtained from a sample of small-enterprise managers confronted with this scenario. Results provide evidence about (1) the type of decisions and actions taken by experienced managers when confronted with the cognitive constraints involved in managerial planning situations; (2) phases and sequence of the process of arriving at planning decisions; and (3) data used and types of analyses performed. Some general implications are drawn from these results with respect to the configuration of a system aiming at supporting managerial planning. These refer to the type of support to be provided at various phases of the planning process, possible features of the human-computer interface, and generic or task/user specific aspects of the system.     

Modal warping: real-time simulation of large rotational deformation and manipulation

This work proposes a real-time simulation technique for large deformations. Green's nonlinear strain tensor accurately models large deformations; however, time stepping of the resulting nonlinear system can be computationally expensive. Modal analysis based on a linear strain tensor has been shown to be suitable for real-time simulation, but is accurate only for moderately small deformations. In the present work, we identify the rotational component of an infinitesimal deformation and extend traditional linear modal analysis to track that component. We then develop a procedure to integrate the small rotations occurring at the nodal points. An interesting feature of our formulation is that it can implement both position and orientation constraints in a straightforward manner. These constraints can be used to interactively manipulate the shape of a deformable solid by dragging/twisting a set of nodes. Experiments show that the proposed technique runs in real-time, even for a complex model, and that it can simulate large bending and/or twisting deformations with acceptable realism.     

Constraints for the design of variability-intensive service-oriented reference architectures – An industrial case study

ContextService-oriented architecture has become a widely used concept in software industry. However, we currently lack support for designing variability-intensive service-oriented systems. Such systems could be used in different environments, without the need to design them from scratch. To support the design of variability-intensive service-oriented systems, reference architectures that facilitate variability in instantiated service-oriented architectures can help.ObjectiveThe design of variability-intensive service-oriented reference architectures is subject to specific constraints. Architects need to know these constraints when designing such reference architectures. Our objective is to identify these constraints.MethodAn exploratory case study was performed in the context of local e-government in the Netherlands to study constraints from the perspective of (a) the users of a variability-intensive service-oriented system (municipalities that implement national laws), and (b) the implementing organizations (software vendors). We collected data through interviews with representatives from five organizations, document analyses and expert meetings.ResultsWe identified ten constraints (e.g., organizational constraints, integration-related constraints) which affect the process of designing reference architectures for variability-intensive service-oriented systems. Also, we identified how stakeholders are affected by these constraints, and how constraints are specific to the case study domain.ConclusionsOur results help design variability-intensive service-oriented reference architectures. Furthermore, our results can be used to define processes to design such reference architectures.     

Need for recovery from work: evaluating short-term effects of working hours,patterns and schedules

In this paper working hours, patterns and work schedules of employees were evaluated in terms of need for recovery from work. Self-administered questionnaire data from employees of the Maastricht Cohort Study on Fatigue at Work (n = 12,095) were used. Poisson regression analyses and multivariate logistic regression analyses revealed that higher working hours a day and working hours a week generally went together with more need for recovery from work. Overtime work was particularly associated with higher need for recovery from work in both genders. Both male and female three-shift or irregular shift workers had higher odds of elevated need for recovery compared to day workers. When additionally controlling for work-related factors, need for recovery levels among shift workers substantially lowered. This study clearly showed that working hours and schedules are associated with need for recovery from work, with different associations for men and women. Especially the associations between work schedules and need for recovery from work were very interrelated with other work-related factors. Future studies could further investigate the possibility that shift work might function as a proxy of other work-related factors that explain the different levels in need for recovery from work, or that job demands are perceived higher among shift workers and may therefore lead to more need for recovery from work.     

Temporal dynamics of the impact of land use on modal disparity in commuting efficiency

Urban land use is known to affect commuting efficiency according to the excess commuting framework. However, most studies do not include temporal dynamics, and those that do, focus on decadal, yearly, or daily temporal resolutions. However, commuting is not a stationary spatial process. Since people leave home and start their jobs at different times of the day and since traffic congestion varies throughout the day, neglecting hourly dynamics can misestimate commuting efficiency in a region and lead to erroneous policy implications. Another important issue often overlooked in the past is the modal disparity in commuting efficiency and how it evolves during the day. To overcome these limitations, this research examines the commuting efficiency variation by car and public transport by six one-hour periods between 5 AM and 11 AM in Warsaw, Poland, using travel survey data and travel times generated from GPS-based big data for cars and from GTFS for public transport. We develop four different groups of modeling scenarios: no disaggregation, disaggregation by time, disaggregation by mode, and disaggregation by time and mode. Therefore, excess commuting and modal disparity metrics are applied for a total of 21 specific time and mode combinations. The results suggest that commuting efficiency is worst during the 8–9 AM period for both modes, and that public transport users are more efficient after 7 AM. Hourly variations in the excess commuting metrics imply that policy makers should examine ways to encourage flexible work hours to distribute work starts and to increase public transport frequencies in the off-peak.     

A macroelement for waffle slab analysis

Behaviour of a waffle slab under transverse loading is investigated through a series of three-dimensional finite element analyses, and modal analysis of a deformed waffle slab cell. “Macroelement” concept is introduced, taking an advantage of the repetitive nature of waffle slab cells and the fact that only few deformation modes participate significantly in sustaining transverse loads. Less significant deformation modes are removed with little consequence by appropriate kinematic constraints. The result is a macroelement cell with fewer degrees-of-freedom.The macroelement is shown to retain all the dominant deformation modes of a waffle slab cell. Results from tested example show good performance of the proposed macroelement with considerable amounts of computer time and storage saved.     

Coupling measures between modes and state variables in power-system dynamics

A new method for model reduction called Selective Modal Analysis uses the eigenvectors and reciprocal eigenvectors of the system matrix A to calculate participation factors associating modes to certain state variables. This paper investigates the idea in depth. The novel aspect of this paper is the use of MacFarlane's concept that the system matrix A represents an energy transformation map to show that the participation factors are actually modal energies. This interpretation has some advantage because of its direct link to stability. It is shown that the participation factors, or modal energies, can be taken to be coupling measures between modes and state variables. An application to a single-machine infinite-busbar system with and without controllers is given. The properties and limitations of these coupling measures are investigated.