2008-06-10 08:58:26

Comparison for /Projects / Onto Wiki / Features of 2008-06-10 08:58:26 and 2010-08-10 13:22:05

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Onto Wiki provides sophisticated means for navigating, visualising and authoring of RDF-based Knowledge Bases. It serves and consumes Linked Data and comprises a comprehensive middleware API for building custom Semantic Web applications.
We refer to it as a Wiki, since our focus is on simplicity, adaptability and collaboration. However, other than annotating text-based Wiki pages with a special syntax (as suggested by text-based Semantic Wiki approaches), Onto Wiki uses RDF in the first place to represent information. For human users, Onto Wiki allows to create different views on data, such as tabular representations or maps. For machine consumption it supports various RDF serialisations as well as RDFa, Linked Data and SPARQL interfaces. Since its introduction in 2006, the application has evolved into a framework for building Semantic Web applications and was recently updated to support the collaboration across multiple domains and application via Semantic Pingback and RDFauthor

Navigation and Visualisation

Onto Wiki provides a number of ways for navigating through RDF knowledge bases.
These include taxonomy and hierarchy browsing (e.g. via SKOS taxonomies or the class hierarchy), facet-based browsing (with complex filter conditions and attribute based tag clouds and full-text search. These different navigation facilities can also be used as a combined navigation, for example a user can start with a full-text search and refine the results using faceted-search or restrict them to a certain part of the selected hierarchy.
Onto Wiki translates these different navigation features into a single SPARQL query. In addition to rendering the results of such a query as a resource list, Onto Wiki provides an extension mechanism for implementing dedicated views like maps and calendars. Once a specific entity has been selected, the resource view displays all available information for that entity. Besides rendering this information generically in a tabular way, OntoWiki can be extended with domain specific resource views (i.e. vocabulary).

Authoring

All views in Onto Wiki can be equipped with corresponding RDFa annotations. Onto Wiki employs the RDFauthor mechanism to automatically transform these views into editable forms. As a consequence, all information items displayed in Onto Wiki can be directly edited in place. This allows OntoWiki users to edit the knowledge base even without being acquainted with the RDF, RDF-Schema or OWL data models. Following the Wiki approach all changes are put under version control and can be easily rolled back.
In addition to this, the integration of RDFauthor as our main authoring mechanism led to two additional usage options:

By using Onto Wiki's RDFauthor bookmarklet, users can collect data from different web pages and import it directly into their personal knowledge bases (e.g. contacts or events).
Onto Wiki can be used as a service for hosting editable mash-ups. These mash-ups use data from Onto Wiki's SPARQL endpoint and other data sources (which are interpreted as named graphs) and provide a merged view on this data. The bookmarklet is able to distinguish the statements from these named graphs and allow the user to edit these data directly inside the mash-up as well as to propagate the changes back to the different sources.

Knowledge Base Evolution

Onto Wiki tries to support the creation of RDF Knowledge Bases from the scratch (rather than using predefined ontologies only) in a wiki way. This means that our users often follow the learning by doing path, where requirements and priorities change over time. Our evolution framework allow Onto Wiki users to apply predefined evolution pattern from a pattern repository to their data, as well as to create their own pattern in order maintain the data quality of their Knowledge Base with little effort. Examples for such evolution patterns include the splitting of classes by using their property values or the transition from a data property to an object property (e.g. the transition from literal based tags to resource based tags).

Linked Data & Semantic Pingback

Onto Wiki acts as a Linked Data server as well as an Linked Data client. Entities that use identifiers being governed by the Onto Wiki installation are automatically served as Linked Data. Onto Wiki supports access control on Linked Data employing the FOAF+SSL protocol as well as traditional local account based authentication. References to entities using foreign identifiers can be de-referenced (i.e. consumed by Onto Wiki) in order to obtain additional information from the original source. Even non-linked data resources can be consumed by utilising specific data-wrapper, that allow the generation of RDF data (e.g. from images, videos or web services).
Often it is beneficial for the owner of a Linked Data resource to be informed about the usage of their resources. When publishing a FOAF profile, for example, it is useful to get notified when others establish a foaf:knows relation. We therefore developed the Semantic Pingback protocol. By employing Semantic Pingback, Onto Wiki users can communicate RDF statements across domains and applications.

Deletions:

This page is intended to give a short description on all relevant OntoWiki features. You can also use it as a starting point for detailed documentation (if existing).

Installation and Management

Guided Installation

Installation of OntoWiki is very easy:

Unpack the archive to your directory
Start your Browser
Go to the Onto Wiki directory and follow the instructions

If you are new to OntoWiki, you maybe want to the read the First Steps Documentation.

User Management

Access Control

From Version 0.7 on, you can manage a detailed model based access control in Onto Wiki. Access to a model can be granted or denied for an account or a group. We distinguish two types of access (read and write).
A detailed description of access control setup options can be found here.

User Interface

Facet-based Browsing

Taxonomic structures give users exactly one way to access the information. Furthermore, the development of appropriate taxonomic structures (whether e.g.
class or SKOS keyword hierarchies) requires significant initial efforts. As a pay-as-you-go strategy, facet-based browsing allows to reduce the efforts for a priori knowledge structuring, while still offering efficient means to retrieve information.
To enable users to select objects according to certain facets, all property values (facets) of a set of selected instances are analyzed. If for a certain property the instances have only a limited set of values, those values are offered to restrict the instance selection further. Hence, this way of navigation through data will never lead to empty results.

Inline Editing

To enable users to rapidly edit or add statements as soon as they notice mistakes or missing information Onto Wiki features an inline editing mode. A double click on a specific literal or resource presents statement editor based on a widget.

Map Tab

If selected data (either a single instance or a list of instances) contains property values representing geographical information (i.e. longitude and latitude coordinates) a map view provides information about the geographical location of the selected data.
Technically, this view is realized by integrating the Google Maps API. However, the integration is bi-directional, since objects displayed in the map can be expanded and instance details are dynamically fetched from the knowledge base and displayed directly within the map view. The selection of instances to be displayed can be furthermore the result of a facet-based filtering.

Calendar Tab

Instances having property values with the associated datatype xsd:date can be displayed in a calendar view. As for the map view the selection of instances displayed in the calendar view can be the result of a facet-based filtering. Each item displayed is linked to the individual view of the corresponding instance.

Resource Auto Suggestion

Property Configuration

Advanced User Interface

History / Versioning Tab

This tab provides the opportunity to track, review and selectively rolled-back changes.

SPARQL Query Shell

With the SPARQL Query Shell advanced users are able to query knowledge bases with arbitrary SPARQL queries.

File / Document Manager

The File / Document Manager allows users to upload documents (e.g. PDF files). These documents get an identifier as normal resources and can be equipped with meta data as normal resources. In addition to that, these file resources can be received over the net as normal download if they have an URI which is part of the the managed namespace of Onto Wiki (e.g. Onto Wiki is installed at http://ow.example.com and the document has the URI http://ow.example.com/files/example.pdf)). The File Manager is accessible over the main menu -> Extras -> File Manager.

Extensibility

Themes

From version 0.6 on, Onto Wiki can use different than the default theme. To create a new theme, copy the directory themes/default to themes/NewThemeName.
The most important theme files are:

css/default.css – the default style sheet, change colors and fonts here
templates/main.php – the main screen, change overall arrangement here

Widgets

Widgets are reusable components of the Onto Wiki user interface that the user interacts with. Onto Wiki uses the Erfurt Semantic Web Application Framework for a basic set of RDF related widget. Developers can add widgets for specific relations or schema datatypes.

2007-12-04 16:49:03

Comparison for /Projects / Onto Wiki / Features of 2007-12-04 16:49:03 and 2008-06-10 08:58:26

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File / Document Manager

2007-07-21 16:15:05

Comparison for /Projects / Onto Wiki / Features of 2007-07-21 16:15:05 and 2007-12-04 16:49:03

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User Management

2007-07-21 16:14:46

Comparison for /Projects / Onto Wiki / Features of 2007-07-21 16:14:46 and 2007-07-21 16:15:05

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SPARQL Query Shell

Deletions:

SPARQL Query Shell

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Comparison for /Projects / Onto Wiki / Features of 2007-07-16 20:25:02 and 2007-07-21 16:14:46

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Advanced User Interface

SPARQL Query Shell

With the SPARQL Query Shell advanced users are able to query knowledge bases with arbitrary SPARQL queries.

2007-07-12 10:46:56

Comparison for /Projects / Onto Wiki / Features of 2007-07-12 10:46:56 and 2007-07-12 10:48:12

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Access Control

Deletions:

Model Based Access Control

2007-07-12 10:41:08

Comparison for /Projects / Onto Wiki / Features of 2007-07-12 10:41:08 and 2007-07-12 10:46:56

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Inline Editing

2007-07-12 10:35:58

Comparison for /Projects / Onto Wiki / Features of 2007-07-12 10:35:58 and 2007-07-12 10:41:08

Additions:

This tab provides the opportunity to track, review and selectively rolled-back changes.

AKSW - Projects/OntoWiki/Features

2008-06-10 08:58:26

Navigation and Visualisation

Authoring

Knowledge Base Evolution

Linked Data & Semantic Pingback

Installation and Management

Guided Installation

User Management

Access Control

User Interface

Facet-based Browsing

Inline Editing

Map Tab

Calendar Tab

Resource Auto Suggestion

Property Configuration

Advanced User Interface

History / Versioning Tab

SPARQL Query Shell

File / Document Manager

Extensibility

Themes

Widgets

2007-12-04 16:49:03

File / Document Manager

2007-07-21 16:15:05

User Management

2007-07-21 16:14:46

SPARQL Query Shell

SPARQL Query Shell

2007-07-16 20:25:02

Advanced User Interface

SPARQL Query Shell

2007-07-12 10:48:12

2007-07-12 10:46:56

Access Control

Model Based Access Control

2007-07-12 10:41:08

Inline Editing

2007-07-12 10:35:58

Widgets