Posted:December 5, 2011

Open Semantic Framework Ontology Modularization and Roles within an OSF Instance

For some time now, Structured Dynamics (SD) has been touting the unique advantages of ODapps, or ontology-driven applications [1]. ODapps are modular, generic software applications designed to operate in accordance with the specifications contained in one or more ontologies. The relationships and structure of the information driving these applications are based on the standard functions and roles of ontologies (namely as domain ontologies), as supplemented by UI and instruction sets and validations and rules. When these supplements are added to standard ontology functions, we collectively term them adaptive ontologies [2].

To further the discussion around ODapps, today we are publishing two new documents, using the semantic technology foundation of the open semantic framework. OSF is a comprehensive, open source stack of SD and external tools that provides a turnkey environment for enterprises to adopt semantic technologies and approaches. OSF has been designed from the ground up to be an ontology-driven application framework.

The first new document, posted on Fred Giasson’s blog, provides a detailed discussion of the dozen or so roles ontologies can play within an OSF installation. Fred’s document is geared more to specific properties and configurations useful to deploy this framework; that is, the “drivers” in an ODapp setting. The second new document — this one — is more of a broad overview of the modularization and architecture of the constituent ontologies that make up an OSF installation. Both documents have also been posted to SD’s open content TechWiki [3], which now has about 360 technical articles on understanding and implementing an OSF installation, importantly including its ontologies.

OSF Constituent Ontologies

As presently configured, an OSF installation may typically utilize most or all of the following internal ontologies:

  • The SCO Ontology (Semantic Component Ontology)
  • The WSF Ontology (Web Service Framework Ontology)
  • The AGGR Ontology (Aggregation Ontology)
  • The irON Ontology (Instance Record and Object Notation Ontology)
  • One or more domain ontologies, to capture the concepts and relationships for the purposes of a given OSF installation, and
  • Possibly UMBEL (optional) or other upper-level concept ontologies, used for linkages to external systems.

(Note: the internal wiki links to each of these ontologies also provides links to the actual ontology specifications on Github.)

Depending on the specific OSF installation, of course, multiple external ontologies may also be employed. Some of the common external ones used in an OSF installation are described by the external ontologies document on the TechWiki. These external ontologies are important — indeed essential in order to ensure linkage to the external world — but have little to do with internal OSF control structures. That is why the rest of this discussion is focused on internal ontologies only.

The OSF Ontologies Architecture

The actual relationships between these ontologies are shown in the following diagram. Note that the ontologies tend to cluster into two main areas:

  1. Content (or domain) ontologies, which tend to embody more of the traditional ontology functions such as information interoperability. inferencing, reasoning and conceptual and knowledge capture of the applicable domain; and
  2. Administrative ontologies, which govern internal application use and user interface interactions.

This ontology architecture supports the broader open semantic framework:

(click for full size)

The WSF ontology plays a special role in that it sets the overall permission and access rights to the other components and ontologies. The UMBEL ontology (or other upper-level ontologies that might be chosen) is also optional. Such vocabularies are included when interoperability with external applications or knowledge bases is desired.

Summary of OSF Roles

We can further disaggregate these ontology splits with respect to the specific dozen or so ontology roles discussed in Fred’s complementary piece on ontology roles in OSF. These dozen roles are shown by the rows with interactions marked for the various ontologies:

S
C
O
A
G
G
R
W
S
F
i
r
O
N
D
o
m
a
i
n
U
M
B
E
L
Define record descriptions
Inform interface displays
Integrate different data sources
Define component selections
Define component behaviors
Guide template selection
Provide reasoning and inference
Guide content filtering (with and without inference)
Tag concepts in text documents
Help organize and navigate Web portals
Manage datasets and ontologies
Set access permissions and registrations

One of the unique aspects of adaptive ontologies is their added role in informing user interfaces and supporting specific semantic tools. Note, for example, the role of the content ontologies in informing interface displays, as well as their use in tagging concepts (via information extraction). These additional roles are the reason that these ontologies are shown as straddling both content and administrative functions in the first figure.

See Fred’s piece to learn more about these dozen roles.

Interactions Are More Complex than Arrows

Naturally, a simple drawn arrow between ontologies (first figure) or a checkmark on a matrix (table above) can hide important details of how these interactions between ontologies and components actually work. In an earlier article, we discussed how the whole workflow takes place between users and user interface selections affecting the types of data returned by those selections, and then the semantic components (widgets) used to display them. This example interaction is shown by the following animation:

(click for full size)

The blue nodes show the ontology interactions. These, in turn, instruct how the various components (yellow) and code (green) need to operate. These interactions are the essence of an ontology-driven app. The software is expressively designed to respond to specifications in the ontology(ies) used, and the ontologies themselves embrace some additional properties specific to driving those apps.

Possible Future Directions

ODapps are a relatively new paradigm, from which we continue to learn more about uses and potentials. We have wanted to write the first versions of these two new documents for some time, but have held off as we learned and exploited further the latent potentials in this design. As it stands, we see further potentials in this approach, and will therefore be likely adding new ontologies and capabilities to the general system for some time.

Some of the areas that look promising to us include:

  • A generalized statistical ontology, especially as it can inform data displays in the semantic components
  • Even more capable widgets in business intelligence (BI) uses, with a concomitant expansion of the vocabulary (predicates and classes) in some of the underlying ontologies
  • More aggregation and summation functions supported by the AGGR ontology, and
  • Still further improved permissions and access layers in the WSF ontology.

These potentials arise from the native power of the design basis for ontology-driven apps. Conceptually, the design is simplicity itself. Operationally, the system is extremely flexibile and robust. Strategically, it means that development and specification efforts can now move from coding and programmers to ontologies and the subject matter users who define and depend on them. With these advantages, who can argue with that?


[1] For the most comprehensive discussion of ODapps, see M. K. Bergman, 2011. ” Ontology-Driven Apps Using Generic Applications,” posted on the AI3:::Adaptive Information blog, March 7, 2011. You may also search on that blog for ‘ODapps‘ to see related content.
[2] See M.K. Bergman, 2009. “Ontologies as the ‘Engine’ for Data-Driven Applications“, AI3:::Adaptive Information blog, June 10, 2009, for the first presentation of these topics, but the specific term adaptive ontology was not yet used. That term was first introduced in “Confronting Misconceptions with Adaptive Ontologies” (August 17, 2009). The dedicated treatment of these topics and their interplay was provided in M.K. Bergman, 2009. “Ontology-driven Applications Using Adaptive Ontologies”, AI3:::Adaptive Information blog, November 23, 2009. The relation of these topics to enterprise software was first presented in M.K. Bergman, 2009. “Fresh Perspectives on the Semantic Enterprise”, AI3:::Adaptive Information blog, September 28, 2009.
[3] Slight revisions of these documents have been posted to the TechWiki as Role and Use of Ontologies in OSF and OSF Ontologies Modularization and Architecture, respectively.

Posted by AI3's author, Mike Bergman Posted on December 5, 2011 at 12:01 pm in Ontologies, Open Semantic Framework | Comments (2)
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Posted:November 15, 2011

UMBEL Vocabulary and Reference Concept OntologyImproved Ontology Navigation and Management in Read-only and Editable Forms

This continues our series on the new UMBEL portal. UMBEL, the Upper Mapping and Binding Exchange Layer, is an upper ontology of about 28,000 reference concepts and a vocabulary designed for domain ontologies and ontology mapping [1]. This part four discusses structOntology, the online ontology viewing and management tool that is an integral part of the open semantic framework (OSF), the framework that hosts the UMBEL portal.

Ontologies are the central governing structure or “brains” of a semantic installation. As provided by the OSF framework, ontologies are also the basis for instructing user interface labels and how the interface behaves. The Web is about global access, immediacy, flexibility and adaptability. Why can’t our use of ontologies be the same?

Unlike similar tools of the past, structOntology exists on the same installation as the ontology that drives it. It is a backoffice ontology editing and management tool that is part of the conStruct tool suite, accessible via the OSF admin panel. There is no need to go off to a separate application, make changes, re-import, and then test. structOntology allows all of that to occur locally with the instance in which it resides. Also, there are some important functionality differences — especially finding and selecting stuff and search — that sets structOntology apart from existing, conventional tools.

Yet, that being said, structOntology is also not the complete Swiss Army knife for ontology management. It is designed for local and immediate use. Its spectrum of functionality is not as complete as other ontology frameworks (for example, supporting reasoners, consistency testers or plug-ins). So, for immmediate and locally relevant use, structOntology appears to be the appropriate tool. For more detailed ontology work or testing, other frameworks are perhaps more useful. And, in recognition of these roles, structOntology also has robust import and export capabilities that enable these dual local-detailed use scenarios. For these distinctions, see further the structOntology v Protégé? document.

structOntology comes in two versions. First, there is the read-only version, which can be made publicly available, that is a great aid to ontology navigation and discovery. This is the version viewable on the UMBEL portal. Second, there is an editable version, which is only available to administrators via a back office function within an OSF instance. Some screen shots of this version, plus pointers to more documentation about it, are provided below.

OWL API as a First-class Citizen

What enables OSF to treat ontologies as a first-class citizen — viewable and editable from within the applications in which they operate — results from the incorporation of the OWL API as one of the major engines underlying the structWSF Web services framework, the key foundational basis to an OSF installation. As noted in Part 2 of this series, the OWL API is one of the four major engines supporting structWSF:

The OWL API is the same engine used by Protégé 4, which is why both structOntology and Protégé are fully interoperable.

Besides interoperabilty, the use of the OWL API also means that other OWL API-based tools, such as reasoners or mappers, may be linked into the system. This design is in keeping with our normative view of an ontology tooling landscape, which Structured Dynamics keeps pursuing in a steady, incremental manner [2]. Further, because of its sibling engines, the OWL API and OSF are also able to leverage the other engines supporting structWSF, such as Solr for advanced search or efficient indexing in the RDF triplestore. (The advantages go both ways, too, such as for example enabling the OWL API to feed appropriate ontology specifications to the GATE text processing area for uses such as ontology-based information extraction [OBIE]). All of this makes for a most powerful and capable foundation to an OSF instance.

The Read-Only Version (UMBEL)

Since UMBEL is a reference ontology and the UMBEL portal is an access point to those references and specifications, we really don’t want casual users making modifications to the ontology [3]. For this reason, only a read-only version of structOntology is provided on the portal.

Access to the structOntology function occurs via the Ontology link on the UMBEL portal. Upon access, you are presented with the main structOntology interface:

The organization of the structOntology application presents all currently available and active ontologies listed in the left panel; UMBEL, of course, is the one selected here. Since this is a read-only version, only the View button shows up in the right-hand panel. (For the options available in the editable version, see below.)

View Option

Upon invoking the View option, the hierarchical tree for the selected ontology appears on the left; structural and definitions on the right.

You may expand the tree and explore the structure deeper by either clicking on the tree nodes in the left-hand panel or the item links in the right-hand panel. If there are further levels in the tree, you will get the JavaScript ‘working’ icon and then see the tree expanded with the new node information shown to the right.

Also note that your interaction with the structOntology application is recounted via the “breadcrumbs” listing at the upper left of the application. The green arrow icon allows you to expand or collapse various sections in the display.

Tooltips

The tree labels are themselves based on the preferred labels assigned to things. However, if you want to see the actual ontology URI reference, you can do so via the tooltip when mousing over the item:

Ontology view tooltips

The tooltip shows the full URI path (unique identifier) of the selected item.

Classes Tab

This example has been based on the Classes tab, which are the reference concepts in the UMBEL context. In read-only mode, the basic information presented is the tree structure, the item description and prefLabel, and super and sub class information in the right-hand panel. (More options are available in the editable version; see below.)

Properties Tab

Properties — that is the relations or predicates between items or nodes — are presnted in a similar manner to that for Classes. The Properties tab has the same basic layout and operations as the Classes tab, including similar right-hand panels:

The Editable Version

The editable version of structOntology shares all of the functionality of the read-only version. Besides adding editing capabilities, the editable version also has other functionality related to general ontology creation and management. There is separate documentation for the editable version; the examples below are from a different instance than UMBEL.

The editable version is accessed via the backoffice admin function within an OSF instance. When invoked, it also has more management options presented in the right-hand panel:

We’ll highlight some of the differences from the read-only version below.

Create New Option

The first notable addition is the ability to create ontologies (as well as to delete, or Remove, them):

The URL (such as http://purl.org/ontology/myont#) becomes the base URI for the new ontology. The new ontology is created with a basic structure, from which you only need fill in your new concepts or classes and relationships:

Basic stubbing is provided for the new ontology to help bootstrap its development (not shown). Once created, this new ontology also now appears on the available local ontologies when first invoking the structOntology application.

View Option

Most screens are quite similar to the read-only version with the obvious change of replacing labels with edit boxes. It is via these edit fields that the ontology becomes editable. This change is quite evident for the View screen:

StructOntology view.png

Searching

Searching can take place on the currently active ontology or all loaded (available) ontologies. Note that selection was made above via the radiobutton under the search box.

Also, depending on settings, searching can also take place on only the preferred label, or on alternative labels or descriptions (in fact, all annotations). (This is part of the settings.)

When entering search terms, the system automatically attempts to complete the matching search phrase. A minimum of three entered characters guides this auto-completion functionality:

When search is initiated, the potential results list also auto-completes for what you have already typed into the search box. Upon selection of one of these items (or completion of the full search phrase), the structOntology system issues a search query to the remote server, which then acts to auto-populate the ontology tree on the left-hand panel. In this case, we have selected ‘communitiy facilities’:

The desired search results then automatically expand the ontology tree. This is really helpful for longer ontologies (the example one shown has about 3000 concepts and about 6000 axioms) and means quicker initial tree loading. Once completed, the (multiple) occurrences of the search item are shown in highlight throughout the tree.

Note this search is not necessarily restricted to the actual node label. Alternative labels and descriptions may also be used to find the search results. This greatly expands the findability of the search function. Here is a great example of matching the OWL API engine to Solr underneath a structWSF instance.

Tab Structure

The editable version of structOntology offers more detail in the right-hand panel when Viewing an item. These sections include:

  • Annotations
  • Structural relationships
  • Instances
  • Linkage to characteristics, and
  • Advanced settings.

Each section is editable. All have auto-complete. Each section may also be expanded or collapsed.

General Operations

Each panel has an expand and collapse arrow shown at the upper right of its panel. These causes the panel’s individual entries to either be exposed or hidden. At the right of each entry, new entries can be invoked with the green plus symbol; existing entries can be deleted with the red minus symbol. (See Structural Relationships below.)

In working with each panel, note that each entry also has the search and auto-complete features earlier noted. Drag-and-drop is also contextual into these panels or not, depending on the nature of the item selected in the left-hand panel (tree).

Annotations

Annotations provide the descriptions about the thing at hand and its associated metadata. (These are separately defined under the Properties tab, or as part of the imported ontology specification.) The available annotations are displayed in this panel when expanded:

Entries are simply provided by entering values into the text fields and then Saving.

Structural Relationships

The structural relationships are the means to set parent and child relations between concepts, as well as to instruct disjoint or equivalent class relations. The Structural Relationships panel is the key one for setting the interconnections within the graph structure at the heart of the governing ontology.

Most of the key structural relationships in OWL are provided by this panel. (However, note there are some additional and rarely used structural specifications in OWL. These must be set via a third-party external application. Such potential interactions are made possible via the flexible import and export options with structOntology).

Instances (Individuals)

Another right-hand panel provides the facility to assign individuals to the classes (or concepts) established under the prior two panels. In this case, we are looking at some specific ‘community facilities’ to assign to that concept:

As with the prior panels, a new instance may be added or discarded ones deleted. Individual instances and their characteristics may also be updated or changes.

Linkage to Characteristics

Another aspect to OSF ontologies is the ability to relate concepts to various metadata characteristics or attributes that might describe that concept’s instances. This relationship is done via the dedicated hasCharacteristic property, which is assigned via this right-hand panel:

This option has the specific behavior of allowing one or more properties (characteristics) to be asserted for a given a class (concept).

Advanced Options

Display and widget and other options are set under the Advanced Options panel. One item to note are the widgets that may be assigned for displaying a given information item:

The relationship of widgets (or semantic components) to information items is a deserving topic in its own right. For more information about this topic, see the semantic components category.

Contextual Drag-and-Drop

In edit mode, it is possible to drag items from the left-hand tree panel into the specifications at the right. This is contextual. In this first example, we see an attempt to drop a “class” result (or concept) into the annotation panel, which violates the structure of the system and is therefore not allowed (as shown by the visual red X cues):

However, if we drag and drop from the tree in an allowable structural definition, we get the visual green check as a cue the move is legal:

This functionality and feedback means that only allowable assignments can be dropped into a new structural definition.

Export Option

Another piece of functionality in the editable version is the export option. When invoked, Export brings up the save dialog with the ability to assign an ontology file name:

Upon saving, it stores the currently active ontology in RDF/XML format:

Export is not active in UMBEL do to the large size of the ontology. If you want to obtain it directly, you may do so from the UMBEL ontology CVS.

Import Option

An Import option is available in the editable version. structOntology import supports all OWL API serializations, specifically RDF/XML, N3, Manchester Syntax and Turtle. When import is invoked, a file open dialog is presented that enables you to find the ontology on your local hard drive:

The Import feature has no file extension limitations; make care to pick and assign the proper types for importation.

Via the Import and Export buttons, it is possible to work locally with structOntology while exporting to more capable third-party tools. Then, once use of those tools is complete, Import provides the ability to re-import the updated ontology back into the local collection.

File Options

Finally, as a server-based system accessed via Web services, there are some slightly different concepts necessary to keep in mind when using the editable version of structOntology. These distinctions need to be kept in mind because you might be working with the local version or the one on the main server. These file options are:

  • Save — saves all modifications on the file, on the server. Then, all modifications will be used if you do a Reload
  • Unload — removes the currently active ontology from the local instance, but does NOT remove it from the server. It merely acts to remove that ontology for local use in the current session
  • Remove — a full delete of the ontology, both locally and on the server
  • Update — recreates the serializations files created from these ontologies, like the .SRZ files used by structWSF and conStruct; the ironXML schema used by the semantic components, etc. The Update option is the most common one when updating an ontology locally, for which you want the persistent version on the remote server to be kept in sync
  • Reload — reloads the server version. If prior local work had not been updated, then a reload acts as a way to restore the remote instance to the local one without change..

These are all available via buttons under the main right-hand panel in structOntology and are more fully described in the edit version documentation.

Additional Information

Additional information on structOntology may be found in an online video:

UMBEL small logo

This is the fourth of a multi-part series on the newly updated UMBEL services. Other articles in this series are:


[1] See further the general Wikipedia description of UMBEL or its specification on the official UMBEL Web site.
[2] See especially the second figure and the accompanying discussion in this document.
[3] The appropriate pathway for suggested changes to the UMBEL ontology itself is via its official mailing list.

Posted by AI3's author, Mike Bergman Posted on November 15, 2011 at 1:33 pm in Ontologies, Open Semantic Framework, UMBEL | Comments (1)
The URI link reference to this post is: http://www.mkbergman.com/988/umbel-services-part-4-structontology/
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Posted:November 9, 2011

UMBEL Vocabulary and Reference Concept OntologyThe OSF Browser is Now More Configurable

This continues our series on the new UMBEL portal. UMBEL, the Upper Mapping and Binding Exchange Layer, is an upper ontology of about 28,000 reference concepts and a vocabulary designed for domain ontologies and ontology mapping [1]. This part three deals with the portal’s navigational tool, the concept or relation browser [2]. It is a favorite component of the open semantic framework (OSF).

Discovery and navigation in a graph structure — as is the basis of ontologies and the UMBEL structure — can be difficult. It is made even more difficult when the number of concepts in the object space is large. With 28,000 concepts, UMBEL is one of the largest public ontologies extant. The relation browser is designed specifically to address these difficulties.

The concept browser in UMBEL is invoked via the main menu option or by clicking on the browser icon [] shown in conjuction with a given concept. Here is an example for the concept ‘tractor’:

Note in this case that the More details … link brings you to a detailed concept view, as was covered in the previous part in this series.

With its extreme configurability and flexibility — see further below — the relation browser can be an essential foundation to an open semantic framework installation. But, the best part about the relation browser is that it is fun to use. Clicking bubbles and dynamically moving through the graph structure is like snorkeling through a massive school of silvery fish.

Origins of the Relation Browser

We have been featuring the relation browser since April 2008 when the first UMBEL sandbox was released:

The relation browser is the innovation of Moritz Stefaner, one of the best data and information visualization gurus around. He continues to innovate in large-scale information spaces, and is a frequent speaker at information visualization conferences. Moritz’s Web site and separate blog are each worth perusing for neat graphics and ideas.

Configurability

Since our first efforts with the browser, we have worked to extend its applicability and configurability. The relation browser can be downloaded separately from our semantic components code distribution site.

The relation browser is configured via an XML specification file. Separate specifications are available for the nodes (classes or concept) and connecting edges (predicates or properties). Here are the current configuration options:

NODE PARAMETERS
label
label is the label assigned to a given node; by default, the end of the URI of the type will be used as the label
displayNodeLabel a Boolean value whether to display or hide a label for a specific node
tooltips the tooltip to be displayed when mousing over a specific node
textFont defines the font of the text label on the node; for example: “Verdana”
textColor defines the color of the text label on the node; value in RGB hex format
textSize defines the size of the text to display in the node
image
a URL to an image to use to display at the position of the node
shape a shape of the node to display; available values are “circle”, “block”, “polygon”, “square”, “cross”, “X”, “triangleUp”, “triangleDown”,
“triangleLeft”, “triangleRight”, “diamond”
lineWeight defines the size of the line of the border for the node’s shape
lineColor defines the color of the line of the border for the node’s shape; value in RGB hex format
fillColor defines the color to use within the shape for the node; value in RGB hex format
radius
defines the radius of the node. The radius is an invisible boundary where the edges get attached
backgroundScaleFactor scale factor for the node’s shape background; a scale factor of 1.25 means that it is 125% normal size
textScaleFactor scale factor of the node’s text label
textOffsetX X Offset where to start displaying the text within the node’s shape
textOffsetY Y Offset where to start displaying the text within the node’s shape
textMultilines multi-lines means that each word of a label is displayed on a single line
textMaxWidth maximum width of the text; if longer, then it is truncated with an ellipsis (“…”) appended
textMaxHeight maximum height of the text; if higher, then it is truncated with an ellipsis (“…”) appended
selectedNodeColorOverlay defines a color to overlay on the center (selected) node of the graph; it is defined by a series of 4 different offsets [alpha, red, green, blue] ranging from -255 to 255 in relation to the base node’s values; can, for example, to make the central node of the graph brighter
overNodeColorOverlay defines a color to overlay on a moused over node of the graph; it is defined by a series of 4 different offsets [alpha, red, green, blue] ranging from -255 to 255 in relation to the base node’s values; can, for example, to make a moused over node of the graph brighter
EDGE PARAMETERS
displayLabel the label to display over the center of the edge
tooltipLabel the tooltip to be displayed when mousing over a specific edge
directedArrowHead defines the type of the arrow for the edge; available values are “none”, “triangle”, “lines”
textFont defines the font of the text label on the edge
textColor defined the color of the text label on the edge; value in RGB hex format
textSize defines the size of the text to display on the edge
image a URL to an image to use to display over the edge at middle of the two connected nodes
lineWeight defines the size of the line for the edge connector
lineColor defines the color of the line for the edge connector; value in RGB hex format

 

It is also possible to specify a breadcrumb in association with the browser.

Besides these configurations, the API for the relation browser also provides for methods to:

  • Link Nodes to Objects
  • Link Nodes to Displays

Via these mechanisms, the relation browser can become a central focal point for any OSF installation. See further the specifications for additional ideas and tips.

Some Other Examples

Here are some other examples of relation browsers you can see across the Web:

UMBEL small logo

This is the third of a multi-part series on the newly updated UMBEL services. Other articles in this series are:


[1] See further the general Wikipedia description of UMBEL or its specification on the official UMBEL Web site.
[2] Various clients and users have named this widget a number of things, including spider, concept explorer, relation browser and concept browser.

Posted by AI3's author, Mike Bergman Posted on November 9, 2011 at 6:10 pm in Open Semantic Framework, UMBEL | Comments (1)
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Posted:November 7, 2011

UMBEL Vocabulary and Reference Concept OntologyOSF Integration with Solr Provides Superior Search

This continues our series on the new UMBEL portal. UMBEL, the Upper Mapping and Binding Exchange Layer, is an upper ontology of about 28,000 reference concepts and a vocabulary designed for domain ontologies and ontology mapping [1]. This part focuses on the search function within the UMBEL portal based on the native engines used by the open semantic framework (OSF).

Search uses the integration of RDF and inferencing with full-text, faceted search using Solr. This has been Structured Dynamics’ standard search function for some time, as Fred Giasson initially described in April 2009. It is a very effective way for finding new and related concepts within the UMBEL structure.

Solr, as the Web service-enabled option for its parent Lucene, has most recently become a not uncommon adjunct to semantic technologies, for the very same reasons as outlined herein. However, in 2008, when we first embraced the option, it was not common at all. To my knowledge, within the semantic technology community, only the SWSE (semantic Web search engine) project was using Lucene when we began to adopt it.

The reasons for embracing Solr (or Lucene) are these:

  • Full-text search with a flexible search syntax
  • Ability to add facets (which is very powerful when combined with the structure of RDF)
  • High performance
  • Extensions for locational and time searches and many additional options, and
  • Open source.

Prior to the adoption of add-ons like Solr, RDF-only search suffered from a number of limitations, especially in the lack of a searchable correspondence of labels in relation to the object URIs used in the RDF model (see some of the limitations of standard RDF search).

Because of its advantages, Solr became the first additional main engine underneath our structWSF Web services framework, complementing the central RDF triple store (Virtuosoin most cases). We have subsequently added other main engines, as well, with a current total of four, which other parts in this UMBEL series will later discuss:

Being a main engine underneath structWSF means that datasets are fully indexed and cross-correlated with the capabilities of the other engines at time of ingest. Ingest most commonly occurs when datasets are ingested by the standard import tool; but, it might also be part of the system’s large dataset import scripts or synchronization routines.

The Search Function and Syntax

The standard UMBEL search box is found at the upper left of most site pages. When searching, you may choose these operators or syntax to add to your keywords, for example:

  • park OR city — provides the most results
  • park AND city — both terms must be present; fewer results
  • park city (no quotes) — both terms must be present, and within 5 words of one another; still fewer results, or
  • “park city” — exact phrase in quotes, with the fewest results.

(At present, Booleean operators apply to full-content search, and not filtered search.)

Upon searching, using the default of searching title, alternative labels (synonyms) and description (“TAD”), the standard search results page is displayed:

This page provides the further filtering options of searching by only title, or all content (including the linkings for each concept to its super classes and sub classes, which may produce a quite inclusive results set). These filter options are helpful in being able to sift through the 28,000 concepts within UMBEL.

The results listing provides the UMBEL concept names, their description, their alternative labels and a link [] to view them in the relation browser (to be discussed in more detail in the next part of this series). A simple pagination utility enables the results to be paged.

structWSF Basis and Options

This UMBEL search uses the structWSF Search Web service. It is what ties into the Solr engine to perform the full text searches on the structured data indexed on a structWSF instance. A search query can be as simple as querying the data store for a single keyword, or to query it using a series of complex filters.

Not all of these query syntax or filtering options are active on the UMBEL instance given the simple concept structure of the UMBEL ontology. Turning these options on or off is a relatively straightforward matter of altering some configuration files and ensuring the right parameters are included in the queries issued by the application to the structWSF search endpoint.

Developers communicate with the Search Web service using the HTTP POST method. You may request one of the following mime types: (1) text/xml, (2) application/rdf+xml, (3) application/rdf+n3 or (4) application/json. The content returned by the Web service is serialized using the mime type requested and the data returned depends on the parameters selected.

A. Optional Available Operators

Optionally, the structWSF Search function may be configured to support these operators and conventions. All operators, by the way, must be entered as ALL CAPS:

  • AND, which is the default operator if more than one key word is entered
  • OR, which needs to be specifically entered
  • NOT
  • Phrases, which are denoted by double quotes as this “search phrase”; single quotes are not accepted
  • Wildcard searches on single characters (?) and multiple characters (*), which can be placed anywhere except the beginning of the query term
  • Field searches, whereby the field name is used in the query followed by a colon
  • Nesting, which allows complicated Boolean expressions to be formed (so long as parentheses are balanced), and many more exotic options.

See further the Lucene search engine syntax specification.

B. Optional Available Filters

Each search query can be applied to all, or a subset of, datasets accessible by the requester. Each Search query can be filtered by these different filtering criteria:

  1. Type of the record(s) being requested
  2. Source dataset(s) for the the record
  3. Presence of an attribute describing the record(s)
  4. A specific value, for a specific attribute describing the record(s)
  5. A distance from a lat/long coordinate (for geo-enabled structWSF instance)
  6. A range of lat/long coordinates (for geo-enabled structWSF instance)

These filtering options allow subset searches to occur, as the example above for title and TAD in UMBEL shows. However, these filters can also be combined into more complete and structured selection options as well. For example, this same search utility applied to Structured Dynamics’ Citizen Dan local government sandbox shows how these additional filters may be applied:

  • Clicking on a given “kind” name causes the results display to be restricted to results only for that kind of class.
  • If so selected, the Filter by Dataset tab is also restricted to the datasets that contain results with that class.
  • Once selected, the filter remains in place. To remove it, click on the Remove filter icon [] to restore the “kinds” back to the original listing for this search.

See the example. Such filtering capabilities present all of the “kinds” (actually, classes that have similar members) that are contained within the structure of the individual results that comprise the search results. The number of records (results) returned for each class may also be shown in parentheses.

Single Result (Concept) View

Clicking on an individual instance result in the UMBEL search results view (see above) provides the single result View for that specific UMBEL concept:

This view now provides a detailed description of the UMBEL concept and its structure and relationships. I briefly describe each item denoted by a checkmark.

The concept title and link to the relation browser [] are provided, followed by the actual concept URI identifier. Then the listing shows the alternative labels (synonyms, jargon and acronyms) provided for that concept followed by its (often detailed) description.

The structured information for that concept appears below that material. First shown is the UMBEL SuperType [2] to which the concept belongs, and then its external (non-UMBEL ontology) and internal (UMBEL) super classes and subclasses. There is also the facility to retrieve named individuals (instances) for that concept (see next).

Named Individual Listing

Choosing the ‘Get Entities from Sources’ button may provide example instances for that concept, as is shown below for the ‘Artist’ concept:

Retrieving Named Individuals

This linkage is relatively new for UMBEL (see the version 1.00 release write-up) and is still being expanded. At present, these linkages are limited to only a subset of UMBEL concepts and only linkages to Wikipedia. This aspect of the system is under active development, with more sources and more linked concepts to be released in the future.

UMBEL small logo

This is the second of a multi-part series on the newly updated UMBEL services. Other articles in this series are:


[1] See further the general Wikipedia description of UMBEL or its specification on the official UMBEL Web site.
[2] SuperTypes are a collection of (mostly) similar Reference Concepts. Most of the SuperType classes have been designed to be (mostly) disjoint from the other SuperType classes. SuperTypes thus provide a higher-level of clustering and organization of Reference Concepts for use in user interfaces and for reasoning purposes. Every Reference Concept in UMBEL is assigned to a SuperType; a few are assigned to more than one where disjointedness conditions are not absolute. Each of the 32 UMBEL SuperTypes has a matching predicate for relating to external topics. See further the discusison of SuperTypes in the UMBEL specification.

Posted by AI3's author, Mike Bergman Posted on November 7, 2011 at 8:28 am in Open Semantic Framework, UMBEL | Comments (0)
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Posted:October 17, 2011

Structured DynamicsToday’s Post is a Testimony to the Value of Vacations

My partner, Fred Giasson, today posted the second part of his series on open source. Since returning from a well-earned vacation a few weeks back — after more than three years without a break — Fred has been writing and developing up a storm. As someone said to me last week, “Fred’s on fire!” I could not agree more.

I think Fred’s post speaks for itself as to why and how Structured Dynamics has made a conscious choice to embrace open source. The major reason he puts forth — to bootstrap the company without the need for external investment — is unusual in itself. But one thing he is silent about is why this is a compelling reason. I’ll comment on that.

Fred and I have both worked for others dependent on their capital for our ventures (a few more times in my case). Capital is great for expansion and operations, but it can be deadly when visions requiring patience are in play. Structured Dynamics is only now a bit more than halfway through its five-year plan. While semantics technologies are exciting with a world of upside potential, they have also been incubated in academic labs with (as yet) a general lack of practical deployment. The promise is there, but often the delivery and maturation have been lacking. We are committed to play a visible role in correcting that.

The approach Fred outlines was not perhaps easily available to new startups a decade ago. But now, with open source and the Internet, costs of entry and ongoing development have dropped markedly. Yet, surprisingly, the idea of financing a startup via revenues is still not talked about sufficiently — let alone often used as an actual basis for building a company.

I’ve been fortunate to be able to partner with a young, world-class technologist whose maturity exceeds that of individuals many years his senior. He understands that in order to achieve important visions that the stewardship of those ideas can not be left to venture capitalists committed solely or mostly to gaming terms or near-term returns. We’re placing our bets on the paying customer and our own judgment.

So, it is great to see Fred continue his phenomenal development productivity since he returned from Hawaii. The benefit of his vacation is that we are also now getting his insights on his blog again.