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Use Case Title: Discovery




3 February 2008

Original author

Ken Laskey

Current lead

Ken Laskey (

Last Modified By

Ken Laskey

Primary Actors

User doing search, system maintaining search catalog

Secondary Actors

Application domain

Triggering event

User submits search to system

Purpose/Goals (Summarize what the use case is to accomplish)

Given a populated catalogue of items and a user’s criteria for a particular item potentially listed in the catalogue, identify the best match.

Issues and Relevance to Uncertainty (Summarize how relevant to uncertainty reasoning and representation?)

Terminology mismatches may make it difficult for the system to find the class of items the user intends. (UncAnn - UncertaintyNature: Epistemic; UncertaintyType: Vagueness)

Given the class of items, the user may not unambiguously understand the meaning of the properties by which the class is described. (UncAnn - UncertaintyNature: Epistemic; UncertaintyType: Vagueness)

Given a set of properties of interest to the user, there is uncertainty in trading off the user’s target property values against those of items in the catalogue. (UncAnn - UncertaintyNature: Epistemic; UncertaintyType: Empirical)

Assumptions/Preconditions (List the preconditions necessary for this use case to occur, including description of necessary context)

Required resources (List resources, such as data sources, ontologies, needed for scenario)

  1. Catalog populated by independent entities whose native descriptions may not directly align with the catalog property and value vocabularies. Catalog entries may be collected from other catalogs. Catalog may also contain entries for multiple items, each with its own property vocabulary.
  2. Description of catalog property and value vocabularies.
  3. Description of user property and value vocabularies.

Successful End (Describe what happens if this use case is successful)

The user finds an item sufficiently close to their search criteria and is not hampered by vocabulary differences with those who populated the catalogue.

Failed End (Describe what happens if this use case fails)

The user does not find an item sufficiently close to their search criteria but has an explanation of how the criteria was not met, e.g. there were no screws of the length needed.

Main Scenario (List the sequence of events for the basic course (numbered))

  1. User specifies item of interest, e.g. looking for a MP3 player.
  2. System identifies item class and returns form with list of properties used to describe item.
  3. User provides target search values for properties of interest (e.g., hard drive size, impact resistance, price). System may also support indicating relative importance of search properties chosen.
    • (Uncertainty in whether user understands semantics of properties, whether catalog entry provider entered values consistent with property semantics intended by system, assumed by user. UncAnn - UncertaintyNature: Epistemic; UncertaintyType: Vagueness)

  4. System returns ranked list of item instances, e.g. different models of MP3 players from different producers.

Additional background information or references (Summarize/provide references to information to further describe or characterize use case)

Service oriented architecture (SOA) assumes a world of distributed resources which are accessible across a network. It is assumed that catalogues will exist for different classes of resources, such as SOA services, and the user will be able to search these catalogs for a desired item. Note, a class of items will be described using a list of relevant properties and items belonging to that class will be described by assigning values to these properties. For discovery to occur, there must be some alignment of or mediation between the list of properties used by those populating the catalogue and those searching it. There must also be some alignment of or mediation between the nonnumeric values assigned to the properties, both in describing items for the catalog and defining the search criteria.

Variations (List the alternatives that will not be further decomposed at this time)

Open Issues