Explorator How to

The Explorator is a tool for exploring RDF data by direct manipulation. Explorator’s visual user interface allows users to explore a semi-structured RDF database to both gain knowledge and answer specific questions about a domain, through browsing, search, and exploration.

This document describes the main Explorator’s functionalities and explains how to use them.

1 Menu

1.1 Dropdown Menu

1.1.1 CSS
1.1.2 All Classes
1.1.3 All Properties
1.1.4 Query
1.1.5 Repository

1.2 Keyword Search
1.3 Operations toolbar

1.3.1 Set of Resources
1.3.2 Set operations
1.3.3 Query

2 Facet browsing
3 Interface operations

3.1 Visualizing subjects, predicates and objects
3.2 Detailing resources
3.3 Selecting resources

1 Menu

The menu appears on the top of the Explorator’s window. It carries the dropdown menu, the keyword search and the operations toolbar.

1.1 Dropdown Menu

The dropdown menu holds a list of Explorator’s functionalities.

1.1.1 CSS

The CSS functionality is used to change the color of the Explorator resources, classes and properties. Once clickled in that option, the following panel will be prompted:

In that panel, you can write simple css rules. For example, the css rule below turns all rdf properties in red:

.property { color:red; }

The name of the css rule must be a RDF class name (Person, Property, Country) that you want to apply the rule. Ex.: .class, .resource, .country, .lake, .browser, etc.

1.1.2 All Classes

This functionality returns a set of resources that have, at least, one triple like that:

(resource, rdf:type, rdfs:class)

It returns all resources of the type RDF Class. All resource painted in blue on the interface are RDF Classes.

1.1.3 All Properties

This functionality returns a set of resources that have, at least, one triple like that:

(resource, rdf:type, rdf:property)

It returns all properties from the repository. All resource painted in green on the interface are RDF Properties.

1.1.4 Query

This functionality allows you to build a query in the Explorator.

You build a query by selecting properties (resources in green) and classes (resources in blue) inside a sets and clicking in the query widgets.

For example, you select the property "coverage" and click in the widget "Resource" in the query frame.

Afterwards, two things will happen: The query will be build with the property coverage, and the result will be computed and displayed on the interface.

You can build complex queries as shown below.

1.1.5 Repository

The Repository option allows you defining which sparql endpoint must be used in the queries.

By clicking in that option, the following frame will be displayed on the interface.

You can enable or disable a repository(Sparql Endpoint) whenever you want. Once disabled a repository, It will not be queried by the Explorator.

In that frame, you can also add you own Sparlq Endpoint in the Explorator.

For add a new sparql end point, you must supply a name and the url of your sparql endpoint, and click in the Add button.

1.2 Keyword Search

You can search for a known item using the text field above. The keyword will be searched in the subject, predicate and object of all triples in the repository.

1.3 Operations toolbar

Using the operation toolbar you can operate the resources or the sets of resources. In this toolbar, you can find 2 functionalities: the set operations and the query builder operation.

1.3.1 Set of Resources

You can define a set of resource in two way:

By selecting the elements individually, as shown in the image below:

Or by selecting the whole set.

You can select more than one resource or set by keeping pressed the ctrl key while clicking on the elements or sets.

1.3.2 Set operations

You can do the intersection, union and difference between two set of resources.

First, you must select a set of resources, after click in one of the operations, select another set of resources and then click on the “=” operator shown below:

As result, you will get the union, intersection or difference between the resources.

1.3.3 Query

You can use the operation SPO to make a query in the database. The SPO operations appears in the toolbar as shown below:

To use this operation, you must set, at least, one of the SPO parameter (S, P or O) and click in ‘=’.

2 Facet browsing

In each set on the interface, you can find the operators “F” and “F*”.

Both permite you to facet the set of resources. Once faceted, you can filter the set by the properties of its resources. This mechanism of filtering is called facet browsing.

The function “F” uses a predefine set of facets to build the facet interface. On the other hand, the function “F*” builds a facet interface using all properties available in the resources of the set.

The facet browsing interface is shown below.

Using the example above, once clicked in a facet value “Mini USB” into the facet “local connectivity”, the SET T in the right, will present only 2 elements that have the property “local connectivity” as “Mini USB”, as shown below:

3 Interface operations

3.1 Visualizing subjects, predicates and objects

In each set you can find the functions S, P, O.

These function have a different semantics from the operation SPO that you can find in the Explorator’s toolbar.

In the first case, the S, P and O mean that you can visualize the subjects, the predicates or the objects of the triples in the set. Below, you have a sample of the same set of triples displayed in different views. On the left, you have the subject of the triples, on the middle, all predicates of the triples and on the right all objects. So, you have the same set of triples display in 3 differents ways.

3.2 Detailing resources

On the interface, you almost always see a RDF resource. As shown below:

However, you can view the triples where the resource is subject, predicate or object. When visualizing the subject of a triple, you can click in the “+” icon to get the details of this resource or all triples where it is subject. Below, we have a sample of this functionality. The set on the left is showing the resource, and the set on the right is showing the triples where the same resource is subject.

3.3 Selecting resources

On the Exploretor’s interface, you can select whatever resource or set that you see on the interface. Below, we will show all selectable piece of information on the interface.

Selecting a whole set:

Selecting one or more resources:

Selecting the properties:

Note that you can select properties in different ways.

Selecting objects:

Note that you can select objects in different ways.