Entity URIs - Frequently Asked Questions
Posted on: Sun, 02/08/2009 - 04:10
1. What is EM?
EM is "Entity Markup". EM refers to an entity as it appears in text, disregarding the current context. Meaning if text contains "Moscow in Texas and Moscow in Maine", the resulting RDF will have only one EM for "Moscow". EM provides some basic info about the entity, but most importantly it provides link to all repository entities called " Moscow ".
<rdf:Description rdf:about="http://d.opencalais.com/genericHasher-1/0c44e300-49f5-39ab-84ac-fbdced5c31ec">
EM is "Entity Markup". EM refers to an entity as it appears in text, disregarding the current context. Meaning if text contains "Moscow in Texas and Moscow in Maine", the resulting RDF will have only one EM for "Moscow". EM provides some basic info about the entity, but most importantly it provides link to all repository entities called " Moscow ".
<rdf:Description rdf:about="http://d.opencalais.com/genericHasher-1/0c44e300-49f5-39ab-84ac-fbdced5c31ec">
<rdf:type rdf:resource="http://s.opencalais.com/1/type/em/e/City" />
<c:name>Moscow</c:name>
</rdf:Description>
The green link will lead to you to a Repository page which can contain one of the following:
· Redirection Page: If entity is unique (there is no another entity by the same name in the Repository), there will be a redirection link to entity page in repository.
· Disambiguation Page: If entity is not unique (there are other entities by the same name in the Repository), there will be a list of links to all entities in the Repository by the same name.
· Info Page : If there is no such entity in the Repository, basic data (which is derived from current document) about the entity will be displayed.
2. What is ER?
ER is "Entity Resolution". ER refers to an entity from a text, regarding its context (in other words entity is disambiguated). Meaning if text contains "Moscow in Texas and Moscow in Maine", the resulting RDF will have both ER for "Moscow, Texas" and "Moscow, Maine" (assuming that Repository does contain those entities). ER provides info about the entity as well as link to entity Repository page which contains extended info about the current entity.
ER is "Entity Resolution". ER refers to an entity from a text, regarding its context (in other words entity is disambiguated). Meaning if text contains "Moscow in Texas and Moscow in Maine", the resulting RDF will have both ER for "Moscow, Texas" and "Moscow, Maine" (assuming that Repository does contain those entities). ER provides info about the entity as well as link to entity Repository page which contains extended info about the current entity.
<rdf:Description rdf:about="http://d.opencalais.com/er/geo/city/ralg-geo1/636f6e15-44b1-0d89-017f-e6356385c6f9">
<rdf:type rdf:resource="http://s.opencalais.com/1/type/er/Geo/City" />
<c:docId rdf:resource="http://d.opencalais.com/dochash-1/2797640c-b7d3-3c52-a9db-092ea7ebb1b3" />
- <!-- Moscow -->
<c:subject rdf:resource="http://d.opencalais.com/genericHasher-1/0c44e300-49f5-39ab-84ac-fbdced5c31ec" />
<c:name>Moscow,Texas,United States</c:name>
<c:shortname>Moscow</c:shortname>
<c:containedbystate>Texas</c:containedbystate>
<c:containedbycountry>United States</c:containedbycountry>
<c:latitude>30.9131</c:latitude>
<c:longitude>-94.825</c:longitude>
</rdf:Description>
3. How can I retrieve my document from Open Calais repository ?
just follow the link of you document
<rdf:Description c:calaisRequestID="0ae66255-e4e9-4902-a060-15dc98c9c993" c:id="http://id.opencalais.com/BxkiXhlcYkXgXdUFhx790A"
rdf:about="http://d.opencalais.com/dochash-1/2797640c-b7d3-3c52-a9db-092ea7ebb1b3">
just follow the link of you document
<rdf:Description c:calaisRequestID="0ae66255-e4e9-4902-a060-15dc98c9c993" c:id="http://id.opencalais.com/BxkiXhlcYkXgXdUFhx790A"
rdf:about="http://d.opencalais.com/dochash-1/2797640c-b7d3-3c52-a9db-092ea7ebb1b3">
4. Can I view entity/document as HTML/RDF ?
Yes (LinkedData supports both RDF and HTML browsers), just change the URL ending from ".html" to ".rdf" and vice versa.
http://d.opencalais.com/dochash-1/2797640c-b7d3-3c52-a9db-092ea7ebb1b3.html to
http://d.opencalais.com/dochash-1/2797640c-b7d3-3c52-a9db-092ea7ebb1b3.rdf and save the file.
Yes (LinkedData supports both RDF and HTML browsers), just change the URL ending from ".html" to ".rdf" and vice versa.
http://d.opencalais.com/dochash-1/2797640c-b7d3-3c52-a9db-092ea7ebb1b3.html to
http://d.opencalais.com/dochash-1/2797640c-b7d3-3c52-a9db-092ea7ebb1b3.rdf and save the file.
5. How do I know if current entity is ER or EM ?
if "rdf:type rdf:resource" contains /em/ it is EM <rdf:Description rdf:about="http://d.opencalais.com/genericHasher-1/d896ede1-c911-378c-be1f-f764c04dd725">
if "rdf:type rdf:resource" contains /em/ it is EM <rdf:Description rdf:about="http://d.opencalais.com/genericHasher-1/d896ede1-c911-378c-be1f-f764c04dd725">
<rdf:type rdf:resource="http://s.opencalais.com/1/type/em/e/NaturalFeature" />
<c:name>Rhode Island</c:name>
</rdf:Description>
if rdf:resource contains /er/ it is ER
<rdf:Description rdf:about="http://d.opencalais.com/er/geo/city/ralg-geo1/d7bc4e8b-cbf3-b49e-f3e3-a56709eb6e71">
<rdf:type rdf:resource="http://s.opencalais.com/1/type/er/Geo/City" />
<c:docId rdf:resource="http://d.opencalais.com/dochash-1/2797640c-b7d3-3c52-a9db-092ea7ebb1b3" />
- <!-- Moscow -->
<c:subject rdf:resource="http://d.opencalais.com/genericHasher-1/0c44e300-49f5-39ab-84ac-fbdced5c31ec" />
<c:name>Moscow,Maine,United States</c:name>
<c:shortname>Moscow</c:shortname>
<c:containedbystate>Maine</c:containedbystate>
<c:containedbycountry>United States</c:containedbycountry>
<c:latitude>45.0706</c:latitude>
<c:longitude>-69.8911</c:longitude>
</rdf:Description>
What entity types can be resolved ?
Currently the resolvable types are : Geo (Country, City, ProvinceState), Company, Product(electronics).
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I have question related to 3rd question:
How can I retrieve my document from Open Calais repository ?
just follow the link of you document
What do you mean follow the link ? are there any APIs which can be used to extract information for a URI ? I want to extract entity name based on URI but not able to find how to extract, could you please suggest ?
Thanks
Ajay