Chapter 5 : Formative Approaches Workers finish the design

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Chapter 5 Formative ApproachesWorkers finish
the design

• ? ? ?

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Contents

• Purpose
• The formative approach Designing a future
  practice
• Cognitive work analysis Modeling
  behavior-shaping constraints
• Deliberately supporting adaptation Workers
  finish the design
• Two loose ends
• Summary

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Purpose

• To outline a formative framework, CWA
• CWA Being specially tailored to the unique
  demands of Complex STS
• CWA? ??
• To provide a systematic basis for designing
  information systems
• Information systems with the autonomy and support
  that workers need to engage productivity in
  flexible, adaptive behavior
• To give workers some responsibility to finish
  the design
• as a function of the situated context, thereby
  improving safety, productivity and health

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The formative approach Designing a future
practice

• 4??? ??
• Complex STS? ?? Work Analysis? intrinsic Work
  Constraints? ???? Modeling?? ?? ??? ??? ?.
• ??? Work Analysis? Formative Approaches? ??? ???
  ????

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What makes formative approaches unique?

• Characteristics of Each Approaches
• Normative Approaches Focusing on legislating
  Work
• Descriptive Approaches Focusing on portraying
  Work
• Formative Approaches Focusing on identifying
  requirements
• Identifying requirements
• Both technical and organizational requirements
  that need to be satisfied if a device is going to
  support work effectively
• Not uniquely specify a new design, providing many
  alternatives
• Being used to rule out many design alternatives

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Basic Structure of Formative Approaches
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Four Steps of Formative Approaches

• Step1 To identify a set of conceptual
  distinctions
• To be linked to particular types of systems
  design decision
• ?gt Sensor design, DB design, Automation design,
  organizational structure design, training program
  design
• Step2 To develop modeling tool set
• Correspondent to conceptual distinctions
• The tools provide a structured way of realizing
  the conceptual distinctions
• Work Analysis Framework (Step 1 Step 2)
• Conceptual distinctions and modeling tools (Step
  12)
• Any one particular formative work analysis
  framework is composed of different CD and MT, as
  a function of the types of problem for which it
  is intended.

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Four Steps of Formative Approaches

• Step 3 To develop models of intrinsic work
  constraints for a particular application
• Requirements? ???? ?? ????? ?
• Modeling tools provide generic conceptual
  structures, the contents identified by those
  tools will vary across domains
• Different domain ? different semantics, different
  design requirements
• This modeling process is the heart of Work
  analysis
• Step 4 To Move from work analysis to systems
  design
• Each of the work models should have formative
  implications for design
• Ex) some models will help determine the structure
  of information system database
• These design interventions lead to a new STS
• Including a new device and a new corresponding
  organizational structure

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Important points (4 ??)

• Focus on modeling work constraints, not on device
• Focus on the way thing could be by identifying
  novel possibilities for productive work
• ? on the way things should be
• ? on the way things are
• Model based, generalizing beyond particular ways
  of doing work
• Introducing boundaries ? flexible , continuous
  evolutions

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Cognitive work analysis Modeling
behavior-shaping constraints

• Formative approaches? ??
• Formative approaches framework ??
• Contextual design approach (Beyer and Holtzbatt
  1988)
• CWA framework (Rasumussen et al. 1994)

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Conceptual Distinctions

• Work domain the system being controlled
• Independent of any particular workers,
  automation, event, task, goals or interface
• Like a Map
• To show the possibilities for action
• Control tasks the goals that need to be
  achieved
• Independent of how they are to be achieved or by
  whom
• Like a constraints-based task analysis
• To identify the product constraints that govern
  activity on the work domain
• Focus on identifying what needs to done

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Conceptual Distinctions

• Strategies the generative mechanisms by which
  particular control tasks can be achieved
• Description of how it can be accomplished
• Product representation (control tasks) ? process
  representations (strategies)
• Social Organization and Cooperation
  relationships between actors
• Including actors and automations
• Allocation among actors (about area, control
  tasks and strategies), communication between them
  and so on.
• Worker Competencies the set of constraints
  associated with the workers themselves
• Generic human capabilities and limitations
• To identify the knowledge, rules, and skills

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Group 1 The characteristics of the problem
demands that must be satisfied
Group 2 The characteristics of the organization
and actors who will be responsible for satisfying
those problem demands
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Why this order?
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Dynamic reduction in degree of freedom
The size of each set in this diagram represents
the productive degree of freedom for actor Ex)
Larger set ? Many relevant possibilities for
action
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• Work Domain
• A fundamental bedrock of constraints on the
  actions of any actors
• Control Tasks
• To inherit the constraints of the first phase,
  but adds additional constraints as well
• This constraints is a property of the control
  task
• Ex) For some control tasks, some actions must be
  performed before others.
• Strategies
• Two sets for strategies A and B are subsets of
  the work domain set and the constraints set of
  control tasks
• Social-organizational analysis
• Subset of the constraints imposed by previous
  phases
• Multiple structures that could be adapted for any
  one strategy
• Worker competencies
• Workers competency set is nested within the
  social-organizational set for strategy A

? The changes to one layer of constraints
propagate logically to others during work analysis
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Relation to design interventions?

• Work domain
• What information is required to understand its
  state ? sensor? model design? ??? ??
• To reveal the functional structure of the system
  ? Database design
• Control Tasks (Ref Mitchell Saisi 1987)
• Not with data structure, but with control
  structure
• ??? ? ?? ??? ?? constraints ? To design
  constraints-based procedure
• To identify what variables and relations in the
  work domain ? To design context-sensitive
  interface mechanisms that present workers with
  the right information at the right time

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Relation to design interventions?

• Strategies
• Not just with what needs to be done but also how
  it is to be done
• Each strategy is regarded as a different frame of
  reference for pursuing control task goals, each
  with its unique flow and process requirements. ?
  what types of human-computer dialogue models
  should be designed
• ? Also to specify the process flow for each
  dialogue mode
• Social-organizational analysis
• Role allocation, Organizational structure
• Worker competencies
• SRK ? Selection and training
• How information should be presented to workers
  (Interface form) Ref. Vicente Rasmussen 1992

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Five Phases of CWA and Design Interventions
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Deliberately supporting adaptation Workers
finish the design

• ?? (Part III ?? CWA? ?? ?? ?? ?? ???)
• What is the intended role of workers?
• Reconciling modeling flexibility Formative
  ?Normative
• Behavior-shaping constraints
• Support workers in finishing the design
• Centralized versus Distributed control
• With freedom comes responsibility
• Two examples of the paradigm
• Taking stock implications for safety,
  productivity and health

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What is the intended role of workers?

• CWA is all about designing for adaptation
• Norros(1996) FMS?? ??? 3?? disturbances? ??
• Workers must adapt in real time to disturbances
  that have not been, or cannot be foreseen by
  designers
• ???? ?? ????? ???? ?? disturbance? ??
• We should design computer-based information
  systems to help workers be effective and reliable
  adaptive actors

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Reconciling modeling flexibility Formative
?Normative

• Questions
• How can we reconcile the analytical goal of
  formative modeling with the design goal of
  supporting flexible, adaptive actions?
• Normative modeling? ??? ?? ???.
• The key to reconciling lies in the concept of
  constraints
• Constraints remain invariant the presence of
  context-conditioned variability
• They provide a basis for reconciling formative
  modeling (by specifying boundaries) and worker
  adaptation (by giving workers the flexibility to
  adapt within those boundaries)

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Behavior-shaping constraints

• Intrinsic work constraints are behavior shaping
  because they define the boundaries on action
• Each of five layers identifies a category of
  constraints that needs to be respected
• This constraint boundary will change as a
  function of the context
• ??? Behavior-shaping constraints? ?????? ??? ? ??
  
• ?? ??? ??, ?? ???? ?? trajectory ?? ??, ?? ???
  ?? trajectory ?? ??,

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Constraints-based approach
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Support workers in finishing the design

• Workers may make changes to their devices
• Permanents design deficiency
• Temporary ??? ??
• Workers must deal with the contingency online in
  the real time because the relevant information is
  only available locally (ex alarm set point
  change)
• It would be preferable if we could design a
  device so that workers could finish the design in
  a more systematic fashion.

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Temporary tailoring activities
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Centralized versus Distributed control

• Centralized control
• Taylors approach to work analysis (1911)
• Identify the optimal way of doing the job by
  designer
• The centralized/distributed distinctions lies on
  a continuum
• In general, the more open system is, the greater
  the need for worker discretion, and thus the
  greater the need for distributed control.
• In a nuclear power plant, some control tasks ?
  completely automated, others require workers to
  be adaptive problem solvers

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Operation
Operation
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With freedom comes responsibility

• Questions Is the philosophy of finishing the
  design flawed?
• Answers
• An open system with unanticipated event can not
  be dealt with by designers
• The demands on workers can be made manageable by
  providing workers with the types of information
  support that is required to finish the design
  effectively

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Two examples of the paradigm

• Good examples of distributed control
• Example 1 A novel alarm system for process
  control plants
• In case of maintenance test
• User-initiated notification (UIN)
• Example 2 A novel decision support system that
  was developed in academia for a medical
  application
• Instead of centralized control, identifying
  constraints and making critiquing systems
• This systems merely advices workers when it
  believes that they have done something wrong
  (Guerlain 1995)

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Taking stock implications for safety,
productivity and health

• Four objectives must be satisfied
• Support worker adaptation and flexibility
• Identify the functionality
• Be based on an understanding of human capability
• Improve decision latitude

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Two loose ends

• Data describe, model generalize
• Explain the complementary relationship between
  descriptive and formative approach
• Useful models can not developed in the absence of
  data and data can not be strongly linked to
  design without being organized into models

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Two loose ends

• What about evolutionary design?
• Applicability of CWA to evolutionary, rather than
  revolutionary, design problem
• There are some design decisions that are frozen
  and therefore must be considered as input into
  the work analysis ? output in revolutionary
  design problem

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Summary
Cognitive Work Analysis Framework
Cognitive Work Analysis
Systems Design
Identify
Form
Realize
Build
Develop
Conceptual Distinctions
Modeling Tools
Models of Intrinsic Work Constraints
Systems Design Interventions
1. Work Domain
1.
1.
1. Sensors, models, database
2. Control Tasks
2.
2.
2. Procedures, automation, context-sensitive
interface
3. Strategies
3.
3.
3. Dialogue modes, process flow
4. Social-Organizational
4.
4.
4. Role allocation, organizational, structure
5. Worker Competencies
5.
5.
5. Selection, training, interface form