On the semantic Web, everything is a “resource”. A resource can be seen as an "entity", or sometimes also called a Thing. This thing can be a person, an album, a place in the World, etc. Each entity is described by its properties: the age of a person, the name of an album, the population of a city, and so forth.

The Zitgist DataViewer reads all the information available for these entities, and displays it so that users can easily read and understand related, contextual information.

The first step performed by the DataViewer is to get information about the entity and to create the Web page that will be presented to users..

Each entity is represented in a table (Figure 1), in this case the information about a person named Ivan Herman. 

Figure 1 These are the six main sections in this table:

1. Tab. This tab displays the type of the entity. In this case, Ivan is a Person. If the table is collapsed (see section about Tools), the name of the entity will be displayed in the tab instead of the type.
2. General information. This section displays general information about an entity. In this example, since the entity is a person, the name of that person, his contact information, his location and a photo of the person are displayed.
3. Tools. These tools are used to perform actions on the table entity.
4. See-more. This section aggregates all the same properties describing a person. By clicking on “see-more”, the complete list of properties is displayed to the user. This feature gives an additional means for users to manage information overload.
5. References. This section lists all other entities referring to the viewed entity. For example, in this case the references are each entity that “knows” Ivan, such as friends, co-workers, etc.
6. Information sources. This section displays clickable links to the locations of all Web sites that contributed the actual information displayed in the DataViewer.

There are multiple display formats or “templates” possible depending on the specific type of entity; some of the options are shown below as well as on the Templates page.

The General Information Section

The general information section (Figure 2) is typically the information you might think best describes a particular type of entity. For example, typical information about a person would be name, contact information, location, birthdate, occupation, photo, etc.

Figure 2

Tools

Tools (#3 on Figure 1) are used to perform actions on the entity table. Available tools include:

• mini-Z icon. This displays information available from zLinks about the entity.
• Lookup icon. This shifts the focus of the DataViewer to this particular entity. In some cases you may have more than one entity per URI, or you may want to focus your navigation on an embedded entity, and this tool allows you to only see the currently active entity.
• Up arrow icon. This scrolls the DataViewer up to the page from any entity table.
• Close icon. This collapses any entity table. By clicking on this icon, only the tab becomes apparent.

See-more

This feature is used to aggregate and hide all of the same properties. As shown in Figure 3, if the user clicks on the blue button that says that there are 70 more “Knows” properties, then all known properties will be displayed to the user.

Figure 3

On the other hand, if the user clicks on the “Hide objects” button, this expanded display is then collapsed with the section hidden again. 

Inline Embedding

With the Dataviewer, users have the possibility to embed entities on-the-spot. This means that they don’t have to open a link in another page; they can do it by embedding it in the current page.

If the user moves his mouse over a link within an entity table, he will see a blue right-arrow appearing. If the user clicks on the normal link, then the entity will be opened in a new page.

On the other hand, if the user clicks on the blue right-array, the entity will be embedded on-the-spot.  If the user clicks on the arrow, a progress bar will shows the creation of the entity.

This action results in the entity (Uldis Bojars in this example) being embedded in the current DataViewer page as shown in Figure 4. 

Figure 4

 References

Linked Data entities more often than not refer to other entities. The references section of the DataViewer (Figure 5) thus shows the what other entities refer to the current one being displayed.

Figure 5

 Information Sources

On the semantic Web, everybody can describe anything about everything. The information sources section of the Zitgist DataViewer is used to show the provenance of information.

Paging Tool

In some cases, there may be more than one resource to display to the user for a given data source. If there are more than five resources to display, results are paged, to help the users manage the overflow of information. 

Since the pages are created asynchronously (using AJAX techniques), users may also copy the link from the Web browser to send to others. To do so, the user simply clicks on the “link to this page” icon and then copies the URL. 

Sidebar Tools

Another feature to manage information overload is the addition of sidebar tools: 

Figure 6

Clicking on the first tab displays the “Navigator Sidebar Tool” or on the second tab displays the “Selector Sidebar Tool”. When the tab is re-clicked, the sidebar is closed and hidden. 

Navigator

The Navigator tool (Figure 7) provides an overview of the entities available for a given data source. All entities are aggregated in the same section of the tool depending on their type (all persons together, all documents together, etc.). By clicking on one of these items the user is redirected to the table displaying information about the entity.

Figure 7

Selector

The Selector Sidebar Tool (Figure 8) is used to show and hide entities and properties to the user. By using this tool a user can hide things he doesn’t want to see:

Figure 8

This tool can be really useful to filter or facet information and to keep the amount of content manageable.