Aggregation Identity and owl:sameAs OAI ORE Technical Committee Meeting, Washington, D.C.

Aggregation Identity & owl:sameAs owl:sameAs What do we want to say? Title slide photo of Washington Monument by Flickr user AlbinoFlea See http://www.flickr.com/photos/albinoflea/290380716/ Made available under CC Attribution- NonCommercial 2.0 Generic license

owl:sameAs

What do we want to say?

owl:sameAs Property defined by Web Ontology Language (OWL) States that two URI references refer to the same thing Reflects the “no unique name“ assumption of the Semantic Web i.e. no assumption that all data creators refer to thing using one name/URI multiple data creators may define names/URIs for the same thing (URI Aliases) Widely used in “Linked Data”

Property defined by Web Ontology Language (OWL)

States that two URI references refer to the same thing

Reflects the “no unique name“ assumption of the Semantic Web

i.e. no assumption that all data creators refer to thing using one name/URI

multiple data creators may define names/URIs for the same thing (URI Aliases)

Widely used in “Linked Data”

Identification v Interaction N.B. Dealing here with identification, not interaction If I claim Resource:A owl:sameAs Resource:B, then My assertion says nothing about (set of) representation(s) for Resource:A and Resource:B available at any time Set of representations available for Resource:A may be quite different from set of representations for Resource:B And conversely… If Resource:A and Resource:B have same set of representations, then That alone is not sufficient to support the conclusion that Resource:A owl:sameAs Resource:B

N.B. Dealing here with identification, not interaction

If I claim Resource:A owl:sameAs Resource:B, then

My assertion says nothing about (set of) representation(s) for Resource:A and Resource:B available at any time

Set of representations available for Resource:A may be quite different from set of representations for Resource:B

And conversely…

If Resource:A and Resource:B have same set of representations, then

That alone is not sufficient to support the conclusion that Resource:A owl:sameAs Resource:B

owl:sameAs and Inferences If Resource:A owl:sameAs Resource:B Then Resource:A Prop:P Resource:X => Resource:B Prop:P Resource:X Resource:X Prop:P Resource:A => Resource:X Prop:P Resource:B e.g. Resource:A dc:creator Person:P => Resource:B dc:creator Person:P Resource:A dcterms:created “2008-01-14” => Resource:B dcterms:created “2008-01-14” ReM:R ore:describes Resource:A => ReM:R ore:describes Resource:B

If

Resource:A owl:sameAs Resource:B

Then

Resource:A Prop:P Resource:X => Resource:B Prop:P Resource:X

Resource:X Prop:P Resource:A => Resource:X Prop:P Resource:B

e.g.

Resource:A dc:creator Person:P => Resource:B dc:creator Person:P

Resource:A dcterms:created “2008-01-14” => Resource:B dcterms:created “2008-01-14”

ReM:R ore:describes Resource:A => ReM:R ore:describes Resource:B

What do we want to “say”? If the requirement is to say “Aggregation:A and Resource:R are the same resource” (i.e. URIs are aliases, “Aggregation:A aka Resource:R”) Then Use owl:sameAs But providers must bear in mind what that means, i.e. the inferences which follow, and make assertion only where appropriate If the requirement is to say “Aggregation:A and Resource:R are different resources, related in some way” (i.e. URIs are not aliases) Then Need to clarify what that “related in some way” relationship is Need to define new ORE property (or select existing property from other vocabulary)

If the requirement is to say “Aggregation:A and Resource:R are the same resource” (i.e. URIs are aliases, “Aggregation:A aka Resource:R”)

Then

Use owl:sameAs

But providers must bear in mind what that means, i.e. the inferences which follow, and make assertion only where appropriate

If the requirement is to say “Aggregation:A and Resource:R are different resources, related in some way” (i.e. URIs are not aliases)

Then

Need to clarify what that “related in some way” relationship is

Need to define new ORE property (or select existing property from other vocabulary)

Aggregation Identity and owl:sameAs OAI ORE Technical Committee Meeting, Washington, D.C.