Major Roadmap

From Wontology

This wontology is stored in and maintained by the WontoMedia web server application. WontoMedia is still in development and is very much less than it is ultimately expected to be--after all "If you're not embarrassed by the first version of your product, you've launched too late." This page is a summary of some of the additional features and capabilities planned for WontoMedia going forward, especially those related to WontoMedia's ability to support ontologies that use the full expressiveness of the Web Ontology Language (OWL), and to interchange ontology data using public standards.

Hopefully if you find yourself unable to express the information you want within WontoMedia, the capability you need is somewhere on the list in this page, so you can either wait for the capability you need to be added, or add it yourself. The lists in this page are grouped based on related functionality—the order of items in the page does not represent the order in which they may be added to the system. An ordered list of our near-term development plans can be found in Pivotal Tracker.

Contents 1 Information Finding and Navigation 2 Expressiveness of Ontologies 3 Additional Ontology Relationships Supported by OWL 4 Import or Export of Information 5 Community Features

Information Finding and Navigation

Currently, the only way to access existing items is through the /items page which lists all of them, or by navigating from one item to another through the connections that link them. This is already cumbersom and will only become more so as the amount of data increases. The following features are planned to address this:

Topics

The items and connections contained in a wontology site will be divided up into a number of different groups, each containing information about a specific subject area or topic. We refer to the groups as "topics". In addition to each topic containing its own items and connections, topics will be able to contain other topics to allow better organization. It will be possible to display the list of items or connections for any particular topic (alone, or including all sub-topics), just as it is currently possible to see lists of all the items and connections in the site over all. When selecting items (to be referenced by a connection), selections will be grouped by topic, with the current and related topics available most easily.

Graphic Display of Relationships

Many non-wontology tools for creating or displaying information stored in an ontology provide a graphical display of items and connections, with some type of icon representing each item, and connecting arrows representing the connections. WontoMedia will eventually have such a display in place of the current text tables in item information pages.

Search

We will integrate Google search so that you can search for items and connections within a wontology by the text of their Titles, Names, and/or Descriptions. (For connections, the Titles and Names of the referenced items will be searched.)

Formatting of Descriptions

Currently, the content of long Descriptions can be difficult to read. WontoMedia will eventually support some type of markup language within item Description fields.

Expressiveness of Ontologies

While the connections-referencing-items model is the core of any ontology, there are common variations on this pattern that WontoMedia does not yet support. These include:

Literal Object Values

Right now, the object of a connection must be an item. However, there are many cases where a connection is really intended to express a constant value. For example, consider an wontology that lists cars. This wontology might contain connections like "ACar isOwnedBy JohnSmith". This connection can easily be expressed as WontoMedia operates now, and makes sense because both of the items "ACar" and "JohnSmith" represent real things. But a connection like "ACar hasTheVINNumber 123456789Q" is problematic, because the object isn't really something appropriate to be represented by an item, it is simply an arbitrary constant. Even more obviously inappropriate to be represented by items are the objects of the potential connections "ACar sOdometerAtLastServicing 33,476" and "ACar wasPurchasedNewOn April 20, 2008". It would be unreasonable to create items in the wontology to represent every possible mileage value or every date in the calendar. So, at some point, WontoMedia will support the creation of connections whose objects are simple constants, and will support a variety of common data types for these constants.

Connections as Subjects or Objects of Other Connections

In some wontologies, it will be appropriate to have "statements about" (connections referring to other) connections. For example, usually a connection in an ontology is assumed to represent a fact. However, some connections may repressent assertions that are attributable to specific entities. When searching or using the information in a wontology, it can be important to represent who made the assertion represented by a particular connection. For example, the fact "Fred says TheNewItalianRestraunt is VeryGood" can be represented by two connections. First, "TheNewItalianRestraunt is VeryGood", and then "Fred says ____", where the blank is a reference to the first connection. In information science, a statement that is itself referenced by other statements is said to be reiffied. Connections can be reiffied to indicate other things about them, like the statement "TheParkingLot hasACurrentCarCountOf 52 wasRecordedAt April 21, 2008 17:05:23GMT".

Additional Ontology Relationships Supported by OWL

OWL, the Web Ontology Language, defines a number of specific object and relationship types that are intended to have a consistent meaning across all systems that implement the OWL standard. These relationship types provide for an ontology which contains statements about itself. For example, OWL predicates (relationship types) can be used to make statements about the other relationships in which an item participates, such as constraining the domain, range, or cardinality of an item's relationship, or of the relationships of the children of that item (the instances of a class which an item defines).

In its current state, WontoMedia can express ontologies which use the semantics represented by the following standard entities: rdfs:Resource, rdf:Property, rdfs:subPropertyOf, rdfs:label, rdfs:comment, owl:inverseOf, and owl:SymmetricProperty. Note that any OWL-encoded ontology can be stored in WontoMedia, but the other OWL-defined items are current treated as "generic" without any enforcement of the meanings the standard creates.

The following are several types of OWL-defined relationships for which WontoMedia does not yet enforce the intended semantics.

Constructs Matching Other Features

Once the remaining "Expressiveness" features listed above are implemented, WontoMedia will implement relationship semantics equivalent to those define by OWL's rdfs:Literal, rdf:XMLLiteral, rdfs:Datatype, rdf:Statement, and rdf:value elements.

Standardized Item Information

Currently, the Title and Description of an item are mapped directly to OWL properties (rdfs:label and rdfs:comment, respectively). Support will be added to the basic item creation and display interfaces for the inclusion of one or more web addresses (URIs) as a standard part of each item, which will map to rdfs:seeAlso and rdfs:isDefinedBy.

Item Grouping

Groups can be created with WontoMedia currently simply by creating an item to represent the group, and then using some type of hierarchical property to indicate the items which are contained in the group. However, WontoMedia isn't able to distinguish this from any other kind of hierarchical structure. OWL contains keywords and semantics specifically for indicating groups. While the representative items could be duplicated generically in the current WontoMedia, we will be adding specific support for rdf:Bag and rdfs:Container, so that groups can be presented in pages more compactly and edited more efficiently.

Lists

OWL includes special list-specific semantics, including support for representing the intended use and order of list items. Again, WontoMedia can express the relationships OWL uses for this currently, but will be extended with specific internal support for the semantics of OWLs terms, so that the appropriate groups of items can be displayed as actual lists. The OWL elements defining the semantics that will be implemented for WontoMedia lists include rdf:Seq, rdf:Alt, rdf:List, rdfs:member, rdfs:ContainerMembershipProperty, rdf:first, and rdf:rest.

Classes

OWL contains a number of properties that allow statements to be made about the structure of the ontology itself. For example, some items can be used to define "classes" of other items within the ontology, by associating them with properties that make assertions about their child items. For example, in a wontology used to record facts about an organization's fleet of vehicles, the item "Car" could be created to be the parent of (and define the class for) all of the items representing specific cars in the fleet. So, to relate this with the example above, there would be the statement "ACar isA Car". OWL defines properties that can then be applied to "Car" to establish rules for items which are children of "Car". These rules would be things like "children of 'Car' must have exactly one hasTheVINNumber property". WontoMedia can currently express all of the relationships that OWL uses for class definition, but will eventually also enforce the rules that these relationships establish, and will use them to prompt users to provide all required information/relationships when new items of an existing class are created. The OWL elements defining the class-hierarchy semantics that WontoMedia will implement include structural elements (rdfs:Class, owl:Class, rdf:type, rdfs:subClassOf, owl:allValuesFrom, owl:equivalentClass, owl:equivalentProperty, owl:Nothing, owl:ObjectProperty, owl:sameAs, and owl:Thing) and property-defining elements (rdfs:domain, rdfs:range, owl:AllDifferent, owl:cardinality, owl:maxCardinality, owl:minCardinality, owl:DataRange, owl:DatatypeProperty, owl:differentFrom, owl:disjointWith, owl:distinctMembers, owl:hasValue, owl:complementOf, owl:intersectionOf, owl:oneOf, owl:onProperty, owl:someValuesFrom, and owl:unionOf).

Import or Export of Information

WontoMedia currently has a primitive ability to export and import the full set of items (in YAML format) and connections (in N3 format), but these are intended for backup and restore of a complete wontology by system administrators, and not for regular use. Planned features for interoperability with other standards-based ontology systems include:

XML Data Download/Export

WontoMedia will be able to download its content in RDF-standard XML for an entire wontology site, a complete topic or subtopic, or for an individual item. "Data" items and connections will be separated from any "schema" items/connections the wontology contains based on standards compliance. Those items and connections that can be expressed purely in RDF, without use of any RDFS or OWL elements are considered "data".

XML Schema Export

It will also be possible to separately download the "schema" portions of a wontology or topic as OWL-standard XML, or to download a mixed data-and-schema file (in OWL) for the entire wontology, a topic/subtopic, an item, or an item and all of its children.

XML Upload/Import

WontoMedia will accept the upload of OWL-standard XML files for merging with its existing content. During import, redundant or error-causing items will be skipped.

Community Features

WontoMedia implements a "wiki like" ontology system (hence, a wontology). And as such, an important part of its functionality is the ability for different people to edit and add to a wontology's content, so that the information can be community-owned and ultimately superior to what any one contributor would have produced. There are a number of not-yet-implemented features, all analogous to features common in virtually all wiki systems, related to this:

Accounts and Profiles for Contributors

Currently, WontoMedia does not require people to log-in or otherwise identify themselves in order to make changes. While this will remain a configurable option going forward, WontoMedia will support the creation of individual contributor accounts, so that contributors can be credited with their work, and so that we can support discussions between contributors about changes in the wontologies' content.

Change Tracking for Items and Connections

Along with user accounts, most wiki's record the changes made to the information they contain, and allow previous states of the data to be restored. WontoMedia will eventually support equivalent tracking for changes made to items and connections.