You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@stanbol.apache.org by rw...@apache.org on 2012/05/30 08:43:05 UTC

svn commit: r1344114 - in /incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer: enhancementstructure.mdtext enhancementstructure.png

Author: rwesten
Date: Wed May 30 06:43:05 2012
New Revision: 1344114

URL: http://svn.apache.org/viewvc?rev=1344114&view=rev
Log:
first version for the Documentation of the Stanbol EnhancementStructure

Added:
    incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.mdtext
    incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.png   (with props)

Added: incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.mdtext
URL: http://svn.apache.org/viewvc/incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.mdtext?rev=1344114&view=auto
==============================================================================
--- incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.mdtext (added)
+++ incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.mdtext Wed May 30 06:43:05 2012
@@ -0,0 +1,126 @@
+This document specifies the Structure used by the Stanbol Enhancer encodes features extracted form the parsed [ContentItem](contentitem.html). The Enhancement Structure is based on [RDF](http://www.w3.org/TR/rdf-primer/) technology and defined as [OWL](http://www.w3.org/2004/OWL/) ontology. 
+
+Its two main purposes are to facilitate the:
+
+1. Interoperability between EnhancementEngines: The design of the Stanbol Enhancer is based on the processing of an [ContentItem](contentitem.html) by multiple [EnhancementEngine](engines)s in an [EnhancementChain](chains). Together with the ContentItem API the EnhancementStructure is the key enabler for the cooperation of the different engines. It ensures that enhancements created by one engine can be consumed by the following engines (e.g. the first engine detects the language of the parsed text; the second consumes the language to select the correct NER (named entity recognition) model and create enhancements describing Named Entities contained in the text; the third Engine consumes those Named Entity annotations and creates suggestions for Entities part of an controlled vocabulary).
+2. Consumption of extracted Features: The knowledge structure standardized by this Ontology aims to allow users to consume/process the features extracted from the parsed content. This includes things like:
+    * list all suggested Entities (accept/reject Tags)
+    * list all suggested Topics (content classification)
+    * group Entity suggestion based on detected "Named Entities" (disambiguation support)
+    * show the occurrence of detected Entities within the analyzed text (similar to spell checker UIs)
+
+    The last section of this document provides a more detailed look at those usage scenarios.
+
+This document first specifies the Enhancement Structure consisting of the Ontology as well as additional rules  [EnhancementEngine](engines)s need to consider when writing Enhancement. In the second part this document focuses more on the consumption of Enhancements by users of the Stanbol Enhancer.
+
+## Overview
+
+The Stanbol Enhancement Structure is a central part of the [Stanbol Enhancer](index.html) architecture as it represents the binding element between the [ContentItem](contentitem.html) analyzed by the the [EnhancementEngine](engines)s as configured by an [EnhancementChain](chains). Together with the [ContentParts](content item.html#content-parts) it represents the state that is constantly updated during the enhancement process.
+
+The following graphic provides an overview on how the EnhancementStructure is used by the Stanbol Enhancer to formally represent the enhancement results.
+
+![EnhancementStructure Overview](enhancementstructure.png "Overview of the Stanbol Enhancement Structure showing 'Bob Marley' recognized as Person within the parsed Text with two suggested Entities 'Bob Marley' the musician and 'Bob Marley' the comedian")
+
+The above figure shows three Enhancements: One TextAnnotation created by the NER (NamedEntityRecognition) engine and two EntityAnnotation that suggest/link Entities as defined by [DBpedia.org](http://dbpedia.org).
+
+The bold relations within the figure are central as they show how the EnhancementStructure is used to formally specify that the mention "Bob Marley" within the analyzed text is believed to represent the Entity [dbpedia:Bob_Marley](http://dbpedia.org/resource/Bob-Marley). However it is also stated that there is a disambiguation with an other person [dbpedia:Bob_Marley_(comedian)](http://bpedia.org/resource/Bob_Marley_(comedian)).
+
+The dashed relations are also important as they are used to formally describe the extraction context: which EnhancementEngine has extracted a feature from what ContentItem. If even more contextual information are needed, users can combine those information with the [ExecutionMetadata](executionmetadata.html) collected during the enhancement process.
+
+## General Information
+
+__Used Namespaces__
+
+This provides the list of namespaces used/referenced by the Enhancement Structure
+
+* __fise__ (_http://fise.iks-project.eu/ontology/_): This is the main namespace of the currently used Enhancement Structure. All custom concepts and properties are defined using this namespace. (*)
+* __enhancer__ (_http://stanbol.apache.org/ontology/enhancer/enhancer#_): This is the main namespace of the Stanbol Enhancer defining concepts such as ContentItem, EnhancementEngine, EnhancementChain …
+* __entityhub__ (_http://stanbol.apache.org/ontology/entityhub/entityhub#_)
+: This is the main namespace of the Stanbol Entityhub component. 
+* __dc__ (_http://purl.org/dc/terms/_): The Dublin Core terms standard is also heavily used by the Stanbol Enhancement Structure. Especially to encode metada data, but also to encode relations between extracted information (fise:Enhancement's)
+* __dppedia-ont__ (_http://dbpedia.org/ontology/_): Concepts of this Ontology are used to describe the types of "Named Entities" detected in parsed content.
+* __skos__ (_http://www.w3.org/2004/02/skos/core#_): The SKOS standard is preferable used to describe entries of Thesauri or more generally any type of controlled vocabularies.
+* __rdf__ (_http://www.w3.org/1999/02/22-rdf-syntax-ns#_)
+* in addition [EnhancementEngine](engines)s are free to add/use properties of any additional Ontology (e.g. when adding the rdf:type's of suggested Entities).
+
+_(*) Historical side note: FISE was the name of the Stanbol Enhancer before its [incubation to Apache](TODO: add link). The Enhancement Structure does still use the original namespace for compatibility reasons._
+
+__About Expressiveness:__
+
+All Stanbol Ontologies are encoded using OWL but restrict itself to basic features. Users need to be aware that not all rules defined in this documentation are formally expressed within the Ontology. However all the stated rules are validated by the [EnhancementStructureHelper](http://svn.apache.org/repos/asf/incubator/stanbol/trunk/enhancer/generic/test/src/main/java/org/apache/stanbol/enhancer/test/helper/EnhancementStructureHelper.java) UnitTest utility part of the "org.apache.stanbol.enhancer.test" module. This ensures that EnhancementEngine implementation that validate there enhancement using this utility comply to this specification.
+
+__About Reasoning:__
+
+Apache Stanbol assumes the users will have no reasoning support. Because of that EnhancementEngines are required to materialize information that would be otherwise only available by reasoning (e.g. it is required that they add both "fise:TextAnnotation" and "fise:Enhancement" as "rdf:type"s when writing a TextAnnotation).
+
+## Core Concepts
+
+The main concept of the Stanbol Enhancement Structure is the "fise:Enhancement". It is used as base concept for all annotation types and defines the generic properties every enhancement MUST provide (e.g. creator, creation date, extracted-from, confidence). On top of the "fise:Enhancement" three specific annotations types are defined:
+
+* TextAnnotation: To describe features with there occurrence within the parsed Text
+* EntityAnnotation: To suggest (linked) Entities with features detected within the content
+* TopicAnnotation: To classify (link) the parsed content along topics
+
+### fise:Enhancement
+
+Every feature extracted by an [EnhancementEngine](engines) that is expressed using the Stanbol Enhancement Structure needs to be represented as a RDF resource with the "rdf:type" "fise:Enhancement".
+
+Enhancements use [Dublin Core terms](http://dublincore.org/documents/dcmi-terms/) to provide metadata about their creation:
+
+* __dc:creator__ _(required, single)_: The [EnhancementEngine](engines) that created the Enhancement. Currently the full qualified name of the Java Class implementing the engine is used as String values. In future version this will change to the relative URL of the EnhancementEngine (e.g. "/enhancer/engine/{engine-name}")
+* __dc:created__ _(required, single)_: The UTF date/time when the enhancement was created by the EnhancementEngine.
+* __dc:contributor__ _(optional, multiple)_: Additional [EnhancementEngine](engines) that contributed to the Enhancement.
+* __dc:modified__ _(optional, single)_: The last change to a given enhancement.
+
+The following properties provide information about the enhancement
+
+* __fise:extracted-from__ _(required, single)_: The URI of the "enhancer:ContentItem" the feature was extracted. EnhancementEngines need to use the UriRef returned by ContentItem#getUri() as value.
+* __fise:confidence__ _(optional, single, range: 0 <= confidence <= 1)_: The confidence of the enhancement as floating point number. NOTE that while this uses a floating point number as value users should not treat values to be on a rational scale - meaning that an enhancement with a confidence of 0.4 is NOT half as good as one with 0.8!
+* __dc:relation__ _(optional, multiple)_: Specifies that the current fise:Enhancement has a relation to an other fise:Enhancement. Values need to be resources of the "rdf:type" "fise:Enhancement".
+* __dc:requires__ _(optional, multiple)_: Specifies that the current fise:Enhancement depends on an other fise:Enhancement. This is a stronger version of using "dc:relation" and should indicate that if one of the required enhancements is declined/removed this also affects this one. Values need to be resources of the "rdf:type" "fise:Enhancement". NOTE also that Dublin Core terms defines dc:requires as an sub-property of dc:relation.
+
+### fise:TextAnnotation
+
+TextAnnotations are used to select portions parsed textual content by using the following properties:
+
+* __fise:start__ _(optional, single)_: The start character position within the plain text version of the parsed content. Note that the plain text version can be retrieved by using the [multi-part content item support](enhancerrest.thml#multi-part-contentitem-support) of the Stanbol Enhancer RESTful API.
+* __fise:end__ _(required of fise:start is present, single)_: The end character position. This MUST only be present of "fise:start" is also defined.
+* __fise:selected-text__ _(optional, single)_: The text selected by the TextAnnotation. This MUST be the same as the text from index "fise:start" to "fise:end" within the plain text version of the parsed content.
+* __fise:selection-context__ _(required if fise:selected-text is present, single)_: The selection context such as the current sentence or a fixed number of characters/word before and after the selected text. This MUST be present if "fise:selected-text" is defined.
+* __dc:type__ _(optional,single)_: The nature of the selected part of the text (e.g. dbpedia-ont:Person, Organization, dbpedia-ont:Place for Named Entities; dc:LinguisticSystem for language annotations; skos:Concept for abstract things incl. categorizations). Note that dc:type values are just recommendations. Users are free to use different as the recommended one. As an example the [KeywordLinkingEngine](engines/keywordlinkingengine.html) allows users to configure dc:type mappings.
+
+As hinted by the description of the above properties their usage depends on the size of the selected part of the text.
+
+* selection of the whole Document: This is the default and MUST BE assumed if non of the start/end/selected-text/selection-context properties is present
+* selection of a part (e.g. chapter, sentence): The preferred way is to define start/end positions. selected-text and selection-context are inefficient for bigger section as they would duplicate those sections of the content with the RDF graph as literals.
+* Selection of words, word-phrases: In this case it is highly recommended to define start/end as well as selected-text/selection-context. Especially the selected-text and selection-context are important to calculate the exact position of an enhancement in non-plain-text content (e.g. HTML fragments).
+
+NOTE: In future version TextAnnotations might switch to a Model that uses
+
+* fise:selection-prefix: some words/characters before the selected section.
+* fise:selection-head: the first few word/characters of a the selected section within the text. Alternative to fise:selected-text in case bigger sections of the parsed content need to be selected.
+* fise:selection-tail: the last few words/characters of a selected section. To be used together with fise:selection-head.
+* fise:selection-suffix: some words/characters after the selected section.
+
+### fise:EntityAnnotation
+
+EntityAnnotations are used to suggest/link entities recognized within the Text. While fise:TextAnnotations are used for representing the recognition(s) (occurrence(s) within the content) the EntityAnnotation provides information about the referenced Entity.
+
+* __fise:entity-reference__ _(required, single)_: The URI of the referenced entity. In cases several URIs are defined as equal (e.g. by "owl:sameAs") EnhancementEngines need to choose one of the URIs and include the according "owl:sameAs" in the enhancement results
+* __fise:entity-label__ _(required, single)_: The label of the linked entity. While entities may define multiple labels (e.g. for different languages, alternate/preferred …) EnhancementEngines are required to only include a single - the best fitting - label.
+* __fise:entity-type__ _(optional, multiple)_: The types of the linked entity. Usually this is the list of rdf:types. However there might be situations where other Resources are used as types. 
+* __dc:relation__ _(required, multiple)_: The dc:relation property is required for entity annotations. Typically values are "fise:TextAnnotation"s this EntityAnnotation is a suggestion for.
+* __entityhub:site__ (optional, single)_: The name of the Entityhub ReferencedSite managing the the suggested Entity. If this property is present users can dereference the suggested Entity with a GET request to "{stanbol}/entityhub/site/{site-name}/entity?id={entity}" where {site-name} is the value of this property and {entity} is the value of the "fise:entity-reference" property. 
+    NOTE: the values "local" and "entityhub" need to be treated separately. In those cases the GET request need to use "{stanbol}/entityhub/entity?id={entity}".
+
+### fise:TopicAnnotation
+
+TopicAnnotation are used to categorize/classify the parsed content along some categorization system. This is done by suggesting/linking Topics of that categorization system for (possible parts) of the parsed content. A "fise:TextAnnotation" is used to select the part of the content where the linked topics apply.
+
+* __fise:entity-reference__ _(required, single)_: The URI of the topic.
+* __fise:entity-label__ _(required, single)_: The human readable label of the topic. While topics may define multiple labels (e.g. for different languages) EnhancementEngines are required to only include a single - the best fitting - label.
+* __fise:entity-type__ _(optional, multiple)_: It is best practice to use [SKOS](http://www.w3.org/2004/02/skos/) for modeling hierarchical classification systems. If this recommendation is followed than the value of fise:entity-type will be "skos:Concept". However users are free to also use different types with "fise:TopicAnnotation"s. 
+* __dc:relation__ _(required, multiple)_: The dc:relation property is required for topic annotations. It refers to the fise:TextAnnotation specifying the part of the text this topic is applied to.
+* __entityhub:site__ (optional, single)_: The name of the Entityhub ReferencedSite managing the the suggested Entity. If this property is present users can dereference the suggested Entity with a GET request to "{stanbol}/entityhub/site/{site-name}/entity?id={entity}" where {site-name} is the value of this property and {entity} is the value of the "fise:entity-reference" property. 
+    NOTE: the values "local" and "entityhub" need to be treated separately. In those cases the GET request need to use "{stanbol}/entityhub/entity?id={entity}".
+

Added: incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.png
URL: http://svn.apache.org/viewvc/incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.png?rev=1344114&view=auto
==============================================================================
Binary file - no diff available.

Propchange: incubator/stanbol/site/trunk/content/stanbol/docs/trunk/enhancer/enhancementstructure.png
------------------------------------------------------------------------------
    svn:mime-type = application/octet-stream