Expressive Qualities of the One Pixel Display

How one single pixel can display emotion and life and maybe even intent? In the Designing Interactive Artifacts we have been tasked with creating a one pixel display using JavaScript, a browser and mouse input.

In class Mogens Jakobsen argued that a one pixel display is the most basic display type we could work with, and that it would allow us to focus on the feeling of the interaction.

In this post I will be discussing the expressive properties of a one pixel display through concepts from a study in the expressivity of simple point-lights (Harrison et al. 2012), the interaction vocabulary by Lenz, Diefenbach & Hassenzahl (2013) and the Interaction Frogger framework by Wensveen, Djajadiningrat & Overbeeke (2004).

Only being able to show only one color sounds like it will be hard to convey anything meaningful. However considering that the experience of the pixel does not only cover the current state, but is rather a sequence of states that shown in particular order may become expressive. Thus time is an important factor in how this colored surface is perceived. It is not just a color, it can even have a personality.

Lenz, Diefenbach & Hassenzahl (2013) argue that the combination of different interaction attributes can evoke different feelings. Although they do not provide a particular mapping between interaction attributes and feelings, they suggest that the interaction profile is used as a tool for planning the feel of an interface. The interaction vocabulary consists of 22 terms mapped in 11 continuums, that can be used to describe how an interaction feels gentle or powerful, direct or mediated and slow or fast.

Harrison et al. (2012) describe how point-lights can be expressive as well. While the point-lights explored in their research are not interactive, and limited to one color, they argue that they indeed are expressive. From 11 different blinking patterns some of the blinking patterns are found to express particular states of a mobile device, such as hibernation, notification of an event and a processing state.

In this study the lights are limited to a fluctuation of intensity over time, and are thus “sequential and non-persistent” (Harrison et al. 2012). Meaning that the meaning is conveyed in a ordered progression of light intensities and that the information disappears as soon as it has been displayed.

These qualities are also relevant for the one-pixel display we will be working with. In addition to light intensity the one-pixel display have the possibility of changing the hue and saturation of the light, adding two additional parameters to work with.

The output can be described as a sequential and non-persistent display of colors varying in color hue, lightness and saturation. On the input side, the possibilities are less restricted, as javascript allows us to both use conventional inputs such as keyboard and mouse, but also less common sensors such as accelerometer, ambient light sensor, geolocation etc. Combining these inputs with the pixel will hopefully allow us to make programs with very different interaction profiles.


Harrison, C., Horstman, J., Hsieh, G., & Hudson, S. (2012, May). Unlocking the expressivity of point lights. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (pp. 1683–1692). ACM.

Lenz, E., Diefenbach, S., & Hassenzahl, M. (2013, September). Exploring relationships between interaction attributes and experience. In Proceedings of the 6th International Conference on Designing Pleasurable Products and Interfaces (pp. 126–135). ACM.