Cognitive Task Analysis

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A Comparative Appraisal ofA Comparative Appraisal ofCognitive Task Analysis inCognitive Task Analysis in

Human-SystemHuman-System InteractionInteractionPresented by

K.M.TripathiConceptualized by

OB Division, DIPR, DRDO, Ministry of

Defence


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Roadmap to the presentationRoadmap to the presentation

Introduction to Human systemIntroduction to Human system(computer) interaction (HSI)(computer) interaction (HSI)

Different methods of task analysis inDifferent methods of task analysis inHSIHSI

Cognitive Task AnalysisCognitive Task Analysis

Steps of CTASteps of CTA Attaining better Human System Co-Attaining better Human System Co-

ordination by CTAordination by CTA


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r o uman ys emr o uman ys emInteractionInteraction

Natural course of developmentNatural course of development

Industrial development

Rapid change during and afterWorld War II

Information technology revolution


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Different tradition to deal with HSI

Ergonomics by Dutch

Work Analysis by French

Functional Task Analysis by British

Currently researchers and practitioners are movingtowards a user centric model of human systeminteraction

What users want to do? What are their

tasks? What are the nature of their task?


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Towards a user centric paradigm ofHuman System Interaction

Human

Computer

Physicalsetting

Tools

Organization and task requirement

LAYER 1

LAYER 2

LAYER 3


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Historical roots to task analysis

Scientific management- Taylor, 1911

Hawthorne studies- 1927-1932

Herzbergs two factor theory- 1966

Hackman and Oldham- 1975 The Socio Technical System Approach

Categories of task analysis

Efficiency oriented task analysis

Solution oriented task analysis


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Use of Task analysis

Safety

Productivity

Allocation of function

Person specification

Job organization and staffing

Task and interface design

Skill and knowledge acquisition

Performance assurance

Provide bases for design decision


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Areas of Task Analysis

Task data collection

Task description

Task requirement evaluation

Task simulation

Task behavior assessment

Stages of Product Development

Conceive

Design

Implement

Operate


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Hierarchical Task Analysis (HTA)DefinedIt is to used to evaluate an organizations training

needs the underlying technique, hierarchicaldecomposition analyzes and represents the behavioral aspects of complex tasks such as planning, diagnosis and decision making

Steps in HTA Identification of the goal

Description of the goal

Breaking up the tasks

Determining the stop point

P . C Rule


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Advantages of HTA

Provide a model for task execution

Enabling designers to envision a goal,subtasks and operations

Decomposing complex tasks

Disadvantages of HTA

Need to much expertise

Design centric

Lack of focus on socio-cultural processes


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Cognitive Modeling

How brain and body respond with coordination in a

specific course of situation is given by cognitivepsychologists Norman (1988) Natural Mapping.

Norman et al thought about a Model Human Processor(MHP), which assumes that human being is able toperform different information processing operationssuch as comparing, matching and calculating.

Card et. al. developed the engineering model ofperformance called GOMS. According to Card et alGOMS enables the MHPs characterizations of humanperformance to be applied on task analysis.

The purpose of task analysis is to map out theconstrains imposed on behavior by the nature andfeature of task requirements.


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GOMS stands for Goals, Operations, Methods andSelection rules

G Goals is defined as a set of symbolic structures

that defines a state of affairs to be achieved anddefines a set of methods to achieve it.

O Operators are defined as elementary perceptual,motor or cognitive acts whose execution is

necessary to change any aspect of the usersmental state or to affect the task environment.

M Method is defined as description of proceduresto achieve the goal and is one of the ways thatusers store their knowledge.

S Selection rule determines that how user selects aparticular method, and can be used to predictwhich method the user will select on the basis ofknowledge of task environment


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Cognitive Task Analysis (CTA)

Cognitive task analysis is an extension of traditional

task analysis to yield information about theknowledge, thought processes and goal structuresand that underlies the observable performance.(Chipman, Schragen & Shalin, 2000)

The outcome of CTA is description of performanceobjectives, equipment, conceptual and proceduralknowledge and performance standard used by expertwhile performing the task.

There are more than 100 varieties of cognitive task

analysis developed by the practitioners. Cooke (1994)

in his review categorized these CTA techniques in

three broad families of techniques.


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Observation and interviews

Informal and provide much flexibility

Process tracingMore structuredConceptual technique

Well balanced and most formal

Formal models (Wei and Salveendy, 2004)

use simulation to model task in cognitive domain

The five common steps performed in most of the CTAmethods

Collect preliminary knowledge

Identifying knowledge representation

Applying focused knowledge elicitation method

Analyze and verify data acquired

Format results for the intended application

Four families of CTA methods


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Collect preliminary knowledge

Document analysis

Observation Unstructured interviews

Identifying knowledge representation

Learning hierarchy analysis

Applying focused knowledge elicitation method

Concept, process and principles

Critical decision method

Analyze and verify data acquired

Format result for the intended application


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Advantages of cognitive task analysis

A comprehensive approach

Putting goods of all methods together

Interdisciplinary nature

Constructivist context

Less time taking

Domain as well as holistic focus

Variety

More user centric


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Future researches

Applied Cognitive Task Analysis (ACTA)

Cost effectiveness and cost benefit analysis

Usability of the CTA products


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The dreams of yesterdayare the hopes of today andthe realities of tomorrow

Thank you

Documents

Cognitive Task Analysis