The creation of task models is done within the Task Ontology Authoring Tool (TOAT). Based on the results of the real-world survey using initial prototypes, the interface and the features of the tool are as follows.

• An interactive Visio-like 2D drawing canvas where the author can draw arbitrary task hierarchies using elements (shapes) from a palette (through drag & drop).
• A panel where the author can define additional properties (attributes) for any task of the illustrated hierarchy.
• A Mindmap-like mode where the tasks created by the author are automatically rendered in a tree structure (either vertically or horizontally). The vertical/horizontal orientation can be changed by the author at any time.
• A birdview representing the canvas in 1:100 scale. This is very helpful when the task model grows in size. The author can easily pan on the birdview and navigate through the task hierarchy.
• A module where the user can search for a specific task in the graph. This module includes a search field that is automatically completed by the time the user types a part of a task name. In case a task is found, the module scrolls the canvas window to the specified task.
• A module that imports/exports the author's task model expressed in XML. There are two different XML files produced. Both files can be automatically processed and stored in the central Task Knowledge Base of TALOS if needed. The first file describes the graph (shapes, position, colours, etc.), while the other describes the task model, i.e. the task relations (subtask, sequence, etc.) and properties (attributes, input parameters, output parameters, dataflow), as described in deliverable for WP2. The second XML file serves as the basis from which the hierarchical task-based UI of the iPhone is generated.
• A module that performs syntactic validation on the created task models using (a) the XML Schema defined for ToDo, and (b) a number of hard-coded rules for identifying additional contradictions in the model that cannot be captured by the XML schema validation. Authors are informed about possible contradictions or redundancies in the respective model before storing it permanently in the underlying knowledge base.

The TOAT prototype has been developed following the principles of the overall TALOS system architecture. In this setting, the task models created with the tool are stored and retrieved into/from a remote database, the central content repository of TALOS.

The following screencast showcases the features of the editor.