I have spend over a year in Zurich Switzerland working for the Man Machine Interaction group at the Eidgenössische Technische Hochschule Zurich. Here I worked on a prototype light interface to be used with the advanced office lighting of the Zumtobel firm. Their lighting system offers some unique functionality, such as the ability to change the diffuseness and the colour of the light, storing and recalling the brightness, diffuseness and colour settings of all connected lamps, and the possibility to create dynamic, changing light settings. However the interface for this lighting system suffered from two problems: it gave very little indication of how the lighting would be effected by selecting one of the saved settings, and secondly the controls for the more complex functions were too similar and not very intuitive. As a result many of the users were not aware of or just did not use the full functionality of the system.

For the expression of the differences between light settings we decided not to use pictograms or text labels, instead the new interface uses abstract patterns displayed on small colour displays. The colours and the shapes of these patterns are directly linked to the characteristics of the light settings. Each time a new setting is saved the image on the corresponding display changes to reflect the new setting. Already too many products just offer a set of identical buttons labelled with pictograms, forcing users to learn and remember all these symbols. They require a lot of cognitive reasoning from the users, and even then users are in many cases unable to understand let alone use the full functionality of these products. Human beings are however very good at recognizing patterns and making links between seemingly unrelated elements. These abilities are used here to create a less cognitive, more intuitive way of communicating the complex lighting situations. At first the abstract patterns are only used to differentiate between the different settings, at this point the absence of large numbers of pictograms should encourage users to be more playful and experiment with the controls. Then later, while using the system, users can learn the relationships between the patterns and the resulting lighting in a gradual, much more natural way. Eventually enabling them to predict in detail what the lighting will do based on the displayed pattern.

The interface itself consists of a set of four tools: a tool for saving light, an input tool for creating new lighting moods, a tool to manage the light system, and a tool to create light animations. These tools can be freely plugged into and taken out of the wall, making the interface adaptable to the requirements of any situation and any room. For example a small storage room will need far less functions than an exhibition space.

Separating the controls also helps to simplify the interface. In everyday use most users do not need the more complex functions like adding a new light or grouping a number of lights. By removing all unwanted features and infrequently used functions, the number of controls can be significantly reduced for a large part of the users. When functions do become necessary, the interface can always be temporarily adapted by substituting the needed tools. This should result in an interface that comes closer to the simplicity and scale of a normal household light switch, which in turn will hopefully encourage users to play with and use the added functionality.