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Class Exercise I: Use Cases

Deborah McGuinness and Peter Fox (NCAR)

CSCI-6962-01

Week 4 (part II), 2008

Contents• Review of reading, comments, questions?

• Class exercise – use cases in real-time

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Semantic Web Methodology and Technology Development Process

• Establish and improve a well-defined methodology vision for Semantic Technology based application development

• Leverage controlled vocabularies, et c.

Use Case

Small Team, mixed skills

Analysis

Adopt Technology Approach

Leverage Technology

Infrastructure

Rapid Prototype

Open World: Evolve, Iterate,

Redesign, Redeploy

Use Tools

Science/Expert Review & Iteration

Develop model/

ontology

Developed for NASA TIWG

Roles and skill-sets

• Facilitator – you may not be ready to play this role but you will need to ‘pretend’

• Engage some domain experts (they are literate, know the resources; data, applications, tools, etc. and you can share this role)

• You will be the modeler (to extract objects, triples)• You may play the role of a software engineer

(architecture, technology) but you can also ask someone for help with this

• Write as much as you can down• Be prepared to be social - it is a team effort

Developed for NASA TIWG

Use Case Examples:

A US 9th grade teacher is preparing a lesson plan aimed at getting students to learn more about the ‘northern lights’, addressing NSES content standards in earth science. The teacher wants the students to learn the scientific terminology, where the phenomena occurs and retrieve some data or graphics for a recent occurrence. The goal of the lesson plan is the engage students, using authentic data from the aurora, as part of an inquiry-based program.

What would we need to add to this?

Developed for NASA TIWG

Schematic

Developed for NASA TIWG

Note

• Your roles and what is/ is not expected of you• Be prepared to draw on the white board• Keep your scoping in mind as you are proceeding

– Identify objects, processes, actors/roles, organizations (or nouns, verbs, adjectives)

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Developing a service ontology• Use case: find and display in the same projection,

sea surface temperature and land surface temperature from a global climate model.– Name:– Goal:– Summary:– Actors:– Preconditions:– Triggers:– Normal flow:– Alternate flow:– Post condition:– Activity diagram:– Notes

• Find and display in the same projection, sea surface temperature and land surface temperature from a global climate model.

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Reminder: Services• Ontologies of services, provides:

– What does the service provide for prospective clients? The answer to this question is given in the "profile," which is used to advertise the service. To capture this perspective, each instance of the class Service presents a ServiceProfile.

– How is it used? The answer to this question is given in the "process model." This perspective is captured by the ServiceModel class. Instances of the class Service use the property describedBy to refer to the service's ServiceModel.

– How does one interact with it? The answer to this question is given in the "grounding." A grounding provides the needed details about transport protocols. Instances of the class Service have a supports property referring to a ServiceGrounding.

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Service ontology• Climate model is a model• Model has domain• Climate Model has component representation• Land surface is-a component representation• Ocean is-a component representation• Sea surface is part of ocean• Model has spatial representation (and temporal)• Spatial representation has dimensions• Latitude-longitude is a horizontal spatial representation• Displaced pole is a horizontal spatial representation• Ocean model has displaced pole representation• Land surface model has latitude-longitude representation• Lambert conformal is a geographic spatial representation• Reprojection is a transform between spatial representation• ….

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Service ontology• A sea surface model has grid representation displaced pole

and land surface model has grid representation latitude-longitude and both must be transformed to Lambert conformal for display

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Assignments for Week 5• Assignment 2: Use-case Driven Knowledge

Encoding Part I (part II is class presentation, in class 7, due TUESDAY Oct. 14. 1pm ET)

• Reading: Ontology Evolution

Assignment 2• Use-case Driven Knowledge Encoding Part I:

– Develop a use case, ‘on your own’ – to do this you may engage domain experts and other team members.

– You will perform the analysis, ontology modeling and knowledge encoding using the methods and tools you have learned to date and document them.

– You may leverage an existing knowledge base and/or ontologies making it clear what you used, modified and created yourself.

– You will also ask and answer questions about the encoding.

• You will present your use case, using the document format, in class and answer questions. 14