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A introduction to CommonKADS: structured knowledge engineering. Guus Schreiber www.commonkads.uva.nl. Activities in knowledge-system development. Business context modelling. Knowledge modelling. Communication modelling. System design. Why context modeling?.

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A introduction to CommonKADS: structured knowledge engineering

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A introduction to commonkads structured knowledge engineering l.jpg

A introduction to CommonKADS: structured knowledge engineering

Guus Schreiber

www.commonkads.uva.nl


Activities in knowledge system development l.jpg

Activities in knowledge-system development

Business

context

modelling

Knowledge

modelling

Communication

modelling

System

design


Why context modeling l.jpg

Why context modeling?

  • Often difficult to identify profitable use of (knowledge) technology

  • Laboratory is different from the ''real'' world

  • Acceptability to users very important

  • Fielding into ongoing process not self evident

  • Often not clear what additional measures to take


How to analyze a knowledge intensive organization l.jpg

How to analyze a knowledge-intensive organization?

  • describe organization aspects:

    • opportunity/problems portfolio

    • business context, goals, strategy

    • internal organization:

      • structure

      • processes

      • people (staff: functional roles)

      • power and culture

      • resources (knowledge, support systems, equipment,…)

  • do this for both current and future organization

    • comparison, and first decisions on where to go


Worksheets organization model l.jpg

Worksheets Organization Model


Process housing l.jpg

Process “Housing”


Example om 3 for housing l.jpg

Example OM-3 for “Housing”


Knowledge modelling l.jpg

Knowledge modelling

  • Specific type of conceptual modelling

    • Only gradual differences with “general” conceptual modelling

  • Knowledge modelling from scratch is time-consuming and difficult

    • Knowledge reuse is important theme

  • Patterns exist for types of problem-solving tasks

    • Base on typology of problem-solving tasks


Analytic versus synthetic tasks l.jpg

Analytic versus synthetic tasks

  • analytic tasks

    • system pre-exists

      • it is typically not completely "known"

    • input: some data about the system,

    • output: some characterization of the system

  • synthetic tasks

    • system does not yet exist

    • input: requirements about system to be constructed

    • output: constructed system description


Task hierarchy l.jpg

Task hierarchy


Knowledge categories l.jpg

Knowledge categories

  • Task knowledge

    • goal-oriented

    • functional decomposition

  • Domain knowledge

    • relevant domain knowledge and information

    • static

  • Inference knowledge

    • basic reasoning steps that can be made in the domain knowledge and are applied by tasks


Knowledge model overview l.jpg

Knowledge model overview


Domain knowledge l.jpg

Domain knowledge

  • domain schema

    • schematic description of knowledge and information types

    • comparable to data model

    • defined through domain constructs

  • knowledge base

    • set of knowledge instances

    • comparable to database content

    • but; static nature


Constructs for domain schema l.jpg

Constructs for domain schema

  • Concept

    • cf. object class (without operations)

  • Relation

    • cf. association

  • Attribute

    • primitive value

  • Rule type

    • introduces expressions => no SE equivalent


Example rule type l.jpg

Example rule type


Inference l.jpg

Inference

  • fully described through a declarative specification of properties of its I/O

  • internal process of the inference is a black box

    • not of interest for knowledge modeling.

  • I/O described using “role names”

    • functional names, not part of the domain knowledge schema / data model

  • guideline to stop decomposition: explanation


Example inference cover l.jpg

Example inference: cover


Inference structure l.jpg

Inference structure


Task knowledge l.jpg

Task knowledge

  • describes goals

    • assess a mortgage application in order to minimize the risk of losing money

    • find the cause of a malfunction of a photocopier in order to restore service.

    • design an elevator for a new building.

  • describes strategies (methods, PSMs) that can be employed for realizing goals.

  • typically described in a hierarchical fashion:


Uml activity diagram for method control l.jpg

UML activity diagram for method control


Assessment l.jpg

Assessment

  • find decision category for a case based on domain-specific norms.

  • typical domains: financial applications (loan application), community service

  • terminology: case, decision, norms

  • some similarities with monitoring

    • differences:

      • timing: assessment is more static

      • different output: decision versus discrepancy


Example assessment task mortgage assessment l.jpg

Example assessment task:mortgage assessment


Mortgage domain information l.jpg

Mortgage domain information


Assessment abstract match method l.jpg

Assessment: abstract & match method

  • Abstract the case data

  • Specify the norms applicable to the case

    • e.g. “rent-fits-income”, “correct-household-size”

  • Select a single norm

  • Compute a truth value for the norm with respect to the case

  • See whether this leads to a decision

  • Repeat norm selection and evaluation until a decision is reached


Mortgage domain knowledge l.jpg

Mortgage domain knowledge


Template pattern for assessment task l.jpg

Template (pattern) for assessment task

case

abstract

abstracted

specify

norms

select

case

evaluate

norm

norm

decision

match

value


Assessment control l.jpg

Assessment control


Claim handling for unemployment benefits l.jpg

Claim handling for unemployment benefits


Normen en beslisregels voor ww beoordeling l.jpg

Normen:

Verzekerd

Werkloos

Wekeneis

Jareneis

Beslisregels

ALS niet verzekerd of niet werkloos of niet voldoet aan wekeneis DAN geen WW

ALS wel wekeneis en niet jareneis DAN korte basisuitkering

ALS wel jareneis DAN loongerelateerde uitkering

Normen en beslisregels voor WW beoordeling


In applications typical task combinations l.jpg

In applications: typical task combinations

  • monitoring + diagnosis

    • Production process

  • monitoring + assessment

    • Nursing task

  • diagnosis + planning

    • Troubleshooting devices

  • classification + planning

    • Military applications


Example apple pest management l.jpg

Example: apple-pest management


Summary l.jpg

Summary

  • Knowledge engineering is a specialized form of software engineering

  • CommonKADS: model-based approach to knowledge engineering

  • Reuse of task-specific knowledge models is important theme

  • Knowledge model often outlives application


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