Chapter 4 : Descriptive Approaches “ What workers really do ”

1. Chapter 4 : Descriptive Approaches“What workers really do” 홍 승 권

2. Contents • Purpose • Descriptive approaches: Current practice • Why descriptive approaches are not enough? • Existing techniques for getting around the task-artifact cycle • An alternative way of getting around the task-artifact cycle

3. Purpose • Using Four cases • To illustrate the important contributions of descriptive approaches • To identify additional dimensions that must be considered in work analysis • Descriptive approach • One of possible means to investigate intrinsic work constraint, rather than an end itself • Computer-based information systems should not be designed based solely on studies of currents. → Formative Approach

4. Scope of descriptive approaches • Descriptive WA is accomplished by conducting field studies that • document the practical challenges that workers actually face on the job • and the practices that workers have developed to cope with those challenges • Europe VS America • 30 years tradition in Europe • Task VS Activity • Task : Official actions that are prescribed to workers. (Normative approach) • Activity : Informal actions that workers actually perform in practice (Descriptive Approach) • There are many different perspectives in descriptive approaches → 4 categories • A case study from situated action • A case study from naturalistic decision making • A case study from activity theory • A case study from distributed cognition

5. A case study from situated action • Suchman (1987) • Anthropologist • 두 명의 사무직원이 phototype 지원시스템을 사용하면서 photocopying machine를 조작할 때 어떻게 협업하고 interact하는지 조사 • Conversation 분석 • 사람들 사이의 대화는 기계와 사람 사이의 대화를 이해하는 초석 • Theoretical Foil • Artificial intelligence approach to planning • The same perspective to the instruction based approach

6. Suchman(1987) 의 결과 • An instruction-based approach is constrained by limitation on the designers’ ability to predict any users’ action • 작업자들은 지원시스템과 복사기에 나타나는 메시지에 대한 그럴듯한 다른 해석을 했다. • 더구나 작업자들은 지원시스템에서 고려하지 못한 상황을 직면하게 되었다. • Suchman said that purposeful actions are inevitably “situated actions” • Situated actions are responding to “local interactions contingent on the actor’s particular circumstances • 결론 : Actual behavior is far from the rational ideal

7. A case study from naturalistic decision making • Klein(1989) • Experimental Psychologist • 시간압박과 책임감 하에서 소방업무를 수행하는 소방 지휘관의 의사결정과정에 대한 조사 • Retrospective naturalistic studies • 평균 23년의 유 경험자들에게 중요하고 일상적이지 않은 사건들을 서술하도록 요청 • Theoretical Foil • Classical decision making : To follow a thorough and rational approach • 여러 개 평가척도설정, 각 척도의 가중치 산정, 대안들 비교

8. Klein(1989) 의 결과 • 그들의 경험에 따라 상황을 판단하고 행동을 결정 • Why experts “go with the flow” • 분석적이고 규정에 의해 일련의 행위를 선정할 수 있는 시간이 없음 : Too laborious mental deliberations. • Not to find optimal action, but to find satisfactory action (feasible, timely and cost-effective) • 경험자이고 전문가이기 때문에, 환경 속에 informative cues 를 인지할 수 있는 지각능력이 있으며. Action의 선택도 경험에 의해 선택 • 환경 속에 informative cues 를 인지할 수 있고, 이 Cue들에 의해 특정상황을 효과적이고 선택적으로 인지할 수 있다. 이것은 그들에게 친밀한 분류 방법이다. • 상황을 인지할 수 있기 때문에, 그들은 과거의 경험에 비추어 적절한 action이 무엇인지 안다. • 경험의 의존하기 때문에 종종 그들이 인지한 첫번째 대안이 행동 가능한 action이 된다.

9. Klein(1989) 의 결과 • Recognition-Primed Decision-making (RPD) • 소방지휘관은 그들의 경험으로, 효과적이고 시의적절한 방법으로 상황을 인지(recognize)할 수 있다. • 그리고 situation assessment를 관련 행동으로 연계 시킨다. • 결론 : Actual decision making is far from the normative approach prescribed by classic decision theory

10. A case study from activity theory • Bødker(1991) • Computer scientist • The participatory design of computer–based systems • UTOPIA Project • 작업자들이 어떻게 목표를 달성하는지를 조사하기 위해 Descriptive task analysis를 수행하였음. • 미래장치개발을 위해 요구 스팩 설정, 프로토타입 개발 및 시험 • 각 단계에서 사용자 참여 • Theoretical Foil • Anglo-American approach to HCI

11. Bødker(1991) 의 결과 • She wanted to find a systematic framework • Thus, to adopt activity theory originated from the psychology of Soviet union

12. Bødker(1991) 의 결과 • Activity theory could be adapted to the practical needs of HCI and its concepts provided a good descriptive understanding of the idea collected during UTOPIA • Activity theory is the study of goal-directed activity • Instead of focusing on the device, goal-focus • Goal focus의 의미 • 도메인의 semantic에 대한 깊은 이해가 요구됨 • Goal-oriented activity는 문화, 사회적 context내에서 도구를 갖고 수행된다. • Goal-oriented activity는 사람의 기술과 전문성을 이해해야 하고, 시스템은 기술과 전문성의 향상을 돕는다. • 종합적으로, context-conditioned variability

13. A case study from distributed cognition • Hutchins (1995) • Anthropologist • Field study of current practice in the domain of ship navigation • On the navigation bridge of a number of US Navy ships at sea • To understand the nature of human cognition in naturalistic settings • Theoretical Foil • Physical symbol system hypothesis (PSSH) • Such as digital computer, human cognition involves mental information processing driven by well-defined rules and representations stored in human memory.

14. Hutchins(1995) 의 결과 • Information processing are not confined to the brain, but are instead distributed spatially across individuals and artifacts and temporally as a function of the history of a particular culture. • Workers frequently accomplished task goals, not in isolation through mental information processing, but as a functional team through mutual coordination of their actions • Cognition “in the wild” is an emergent activity that is not completely specified ahead of time. • Historical influence of cultures were very important. Many useful artifacts and many of the practices were adapted products of navigational experience. → Not a strict mental activity mechanically performed by an individual.

15. Comparison of four case studies 참고문헌 : Simonsen and Kensing (1997), Suchman (1995)

16. Importance of current practice • 4가지 사례의 차이점 • 다른 배경을 갖은 연구자들에 의해 수행 • 다른 적용분야(영역) • Theoretical foil 이 다름 • 4가지 사례의 공통점 • It is the enormous value of conducting descriptive studies of work in representative or naturalistic settings • Converging characterization of human work • Context-conditioned variability의 중요성 • Human work는 strong social components를 갖는다. • Work is also seldom solely focused on internal mental processing because worker create tools: reducing the burden on scare cognitive resources. • Current work practices are shaped by historic cultural factors. • Time pressure and other constraint하에서 작업을 하지만, 경험을 통해 업무수행에 필요한 전문지식을 쌓는다.

17. Implications for work analysis • Work analysis framework must include at least five dimensions of work • Work domain analysis 필요 • 친숙하지 않은 사건을 다루기 위해 information requirements를 식별하기 위해… • Constraint-based task analysis 필요 • 작업목표를 flexible, situated manner로 달성하는데 도움을 주는 information requirements를 식별하기 위해 … • Effective Strategies의 분석 필요 • 특정 도메인에서 일어나는 어떤 사건을 다시 일으킬 수 있는 메커니즘을 식별하기 위해… • Social and organizational factors를 분석할 필요 • Computer based information system를 만든다는 것은 새로운 조직구조를 만드는 것 –각 개인역할, 팀의 조직, 구성원간의 교신 등 • 요구되는 다양한 Workers’ competences(적성,능력) 식별 • 전문가 행동을 지원하고, skill acquisition을 지원하는 정보시스템을 설계하기 위해…

18. Why descriptive approaches are notenough: The task-artifact cycle • Limitations of basing design solely on current practice • Are these limitations recognized? • From descriptive analysis to design implications: The track record • People are adaptive : the task-artifact cycle • Summary

19. Limitations of basing design solely on current practice • Intrinsic Work Constraints • Constraints on achieving work goals, independent of any particular device • These constraints are an inherent part of work in a particular domain • IWC delimit the actions that are required to get the job done • Current Work Practices • Current practice is device-dependent

20. Current Work Practices Intrinsic Work Constraints Currently Unexplored Possibilities Functional Actions Workaround Activities Why computer-based information systems should not be designed to support current practices.

21. Direction of computer-based information systems design • Currently unexplored actions may require too much time, computational effort, memory demands or knowledge with the existing device. • Then if with the existing information systems, workers may simply decides to omit this tasks • If the requisite computer support were provided, these unexplored possibilities could very well become a productive part of workers’ practices

22. Implications • Computer-based information systems should ideally be designed to support intrinsic work constraints, not just current work practices • Two reasons • We do not want to base our design on the workaround activities that are vestiges of poor device design • We want to support currently unexplored possibilities. • Work analysis는 현 작업보다는 intrinsic work constraints를 식별하는 것이다. 그러나 이것이 descriptive studies의 무용론을 이야기 하는 것은 아니다. • The point is that future designs should go beyond current practice by removing unwanted inefficiencies and by adding new functional possibilities.

23. Are these limitations recognized? • Limitations of Descriptive Analysis • Benyon (1992) : “Embodying current practice in future systems is a fundamental error” • Beyer and Holtzblatt(1998), Holmqvist(1991) • However, • The analysis of current practices should be viewed as one of several possible means to investigate work constraints, rather than an end in itself

24. From descriptive analysis to design implications: The track record • Social science • 현 상황 분석에는 적절하지만, 새로운 정보 시스템 설계에는 부적절 • Activity theory • The descriptive nature of activity theory make it difficult to develop a novel design • Francophone ergonomics community • Human factors community

25. Requirements Identification Workers’ Tasks Design of Artifacts Possibilities for Work Practices People are adaptive : the task-artifact cycle • Task-artifact cycle (Carroll et al. 1991) • 현재 work practice를 기준으로 requirements가 만들어지고 artifact를 디자인한다. • 현장에 배치되면 새로운 work practice가 만들어진다.

26. People are adaptive : the task-artifact cycle • If we conduct a descriptive work analysis to understand workers’ current tasks, we will identify requirements that could be used to design a new artifact

27. Existing techniques for getting around the task-artifact cycle • Rapid prototyping and iterative user testing • To create prototypes of new designs and evaluate them by having workers use them • The end goal is to iteratively maximize the overlap between the two sets • The subset of workaround activities becomes smaller and smaller • The subset of currently unexplored possibilities becomes smaller and smaller • Scenario-based design (Carroll et al. 1991) • Analytical techniques for trying to achieve the same objective ↔ Empirical way • Scenarios provide a means for analytically evaluating “Simulated future work”

28. New Requirements A2 T1 T2 T3 A3 A1 New Possibilities Limitations: The problems of device-dependence and incompleteness • Strong device dependence • A dog chases its tail : continuous iteration process • Incompleteness • Scenarios representation is incomplete : the number and range of tasks • Limitation by the ingenuity and creativity of the designer • EX) Accident data

29. An alternative way of getting around the task-artifact cycle : Modeling intrinsic work constraints • Completeness : The need for models Models provides a more systematic and explicit basis for work analysis

30. Device-independence : focusing on intrinsic work constraints (1) • Model what? • There are many different entities that could be modeled • To find a way escaping from the regress by the task-artifact cycle • To find the set of intrinsic work constraints ↔ Not including workaround activities

31. Device-independence : focusing on intrinsic work constraints (2) • Work analysis methods should not prespecify the follows • Existing set of sensors • Contents and structure of the database • Functionality of the automation • Allocation of functions between computer and workers • Allocations of job responsibilities • Appearance and structure of the interface • Workers’ competences • Because each issues is a point of design leverage → inheriting the vestiges of the old

32. Device-independence : focusing on intrinsic work constraints • The following decisions should be made based on the findings obtained from the work analysis • What information should be gathered • How it should be organized • How to automated • What to automated • How to organize work • How to display information • How to train operators • Ways of identifying intrinsic work constraints • Studying the structure of the work domain : identify efficient tasks and novel strategies • Analytical model (e.g. Operation research) • Current practice

33. Summary • What type of work analysis is appropriate for complex sociotechnical systems? • Normative approaches • Strong limitation • Descriptive approaches • Limitation • Task-artifact cycle: inherit the deficiencies of current practice • To overcome the cycle, prototyping and scenario method • These limitations can be directly addressed by explicitly modeling intrinsic work constraints