# Ontology Visualization

# Basic Usage

NUAO provides a hierarchy of event classes all derived from . They were designed with usage events triggered by the user in mind.

If looking at the example of a file being opened NUAO models one main event which stretches from the time the file is opened to the time it is closed. This is described via and the properties and . During the time span of this event the file can be in the focus of the user or not. This is modelled via instances that describe when a file was in focus. Since users will typically switch the focus between applications and resources very often storing all focus events might result in a very high number of events that are hard to handle. For this purpose NUAO provides which can be used to accumulate the total amount of time the resource was in focus during a .

Since the action of modifying a resource is a very foggy concept and hard to fit into an event with start and end time it was decided to instead only store a timestamp for each modification of the resource. This is described via and . For file modifications one would typically use .

The diagram above shows one main which contains three focus events. (The term contains is only used with respect to the visualization. In fact the instances are only related to the via their start and end time.) In addition the file was saved three times, twice in the first and once in the third.