1.7. Summary

Have a look at the following movie. The last sheep has definitely no sense of orientation and perhaps never heard the word "navigation" (Click on the thumbanil to watch the movie!).

Sheep without orientation (Holy Lemon)

Navigation provide answers to questions like:

Where am I?
Where can I go?
How will I get there?
How can I get back to where I once was?

We normally navigate through the world with our eyes, but sometimes one cannot use his eyes because of various reasons: one might be blind or might be in the dark, etc. Being blind or being in the dark means that we have to use other senses than the eyes to navigate, such as the ears, touch or even smell.

Within multimedia applications we need navigation as well. Multimedia navigation enables to explore information spaces that are too large to be conveniently displayed in a single window. We mainly navigate with our eyes and we cannot rely on sensory perception such as touch or smell. In addition, you have not the same objects as in real space which can be used to get your bearings. Therefore we need navigation tools which guide the user through the information space of a product or web page, helping explore the content and functionalities of a project.

There exist a few principles good navigation tools should follow:
They are intuitive and do not force the user to first study extensive manuals or help documents; they are consistent throughout the whole product: this includes the appearance (e.g. Colours and fonts), the placement and the functionality of the tools; etc.

We distinguish between three navigation types: spatial, temporal and thematic navigation.

Thematic Navigation
Thematic navigation controls the thematic information of a multimedia application. In web pages this is normally the navigation between different files. In interactive 2D maps, thematic navigation often allows to change the appearing of the map or to extract thematic attributes or values out of the map.
Temporal Navigation
Some multimedia applications contain a temporal component. In each time span (minutes, hours, days, etc.) happened specific events that are visualised in the application. Navigating between these events is temporal navigation.
Spatial Navigation
Spatial navigation is the process of orienting and moving through a virtual environment (University of Edinburgh). Spatial navigation is mainly used in interactive 2D maps.

There are several possibilities how to implement these navigation types in multimedia applications. In this lesson we only have looked at web pages and interactive 2D maps. While spatial navigation is only realised in interactive 2D maps, we find thematic and temporal navigation in both application types.

Thematic navigation is subdivided into two structures:

Sequential
Non-Sequential

For web pages, the non-sequential navigation structure can be further subdivided into two types:

Hierarchic Data Structures
Network Data Structures

Temporal navigation is used in applications where time plays an important role. Time is always combined with a theme. The question "What has happened when?" is the most important question in temporal navigation. Therefore, temporal navigation acts like thematic navigation but instead of the theme you select or define the time.

Spatial navigation is mainly used in interactive 2D maps. Panning and zooming controls are employed in nearly all interactive mapping systems and have become "second nature" to those who use computer regularly. Their ubiquitous nature is due to our daily need to visualise large information spaces through small computer windows. (Harrower et al. 2005)

Cartography for Swiss Higher Education

1.7. Summary