A key finding of the Activmon study was that users wanted higher-fidelity social
feedback. Although users already seemed to benefit from having an aggregate,
anonymous indication of group activity, being able to identify individuals in a group could be more conducive to generating the feeling of a social environment around the device. The challenge was to design an interface to show individualised group activity that was simple, intuitive, and visually appealing.
The first design I considered used multiple RGB LEDs, where each LED consistently represented a separate person. One of the LEDs showed the device wearer’s activity, with the others showing the activity levels of other group members on the same red- to-green scale. However, the LED position-to-person mapping in this approach was be non-obvious. The wearer had to remember which LED position corresponded to which person, including their own LED, and the positions needed to be manually labelled on the device itself in case they forgot. This added complexity invalidated the role of the ambient display as a display that could be taken in at a glance. I considered that, in the Activmon study, users’ primary concern regarding the group activity display was that the activity of others was only presented in aggregate. Users were unable to compare their own activity directly to that of others, and this created distrust of the information presented (‘is it just one really active user 2I determined an appropriate threshold, through experimentation, that excluded small acceler-
[generating an activity indication]?’). Users did not, however, express a desire to see how those other users were performing against their own goals. I decided, then, that this granularity of information was not necessary and that a simpler form of group representation was possible.
I therefore developed an alternative design which used fixed colours as a way to identify individuals, and a positional ranking system as a way of providing a user with a method of gauging others’ activity in comparison to their own. Each indi- vidual in a group of users with linked devices was assigned a consistent colour. This connection between user and colour was made clearer by having each user in the group wear a device of that colour. For example, Alice might have a device made of a blue material, Bob might have a cyan device, and Carol might have a magenta coloured device. However, the user’s colour would not necessarily be seen as part of their own display.
The devices themselves would have several RGB LEDs arranged in a straight line. A single middle LED would consistently operate in the same way as the Activmon LED but with the new sliding window continuum display, changing from red to yellow to green depending on the wearer’s own physical activity. The LEDs above and below this middle light would turn on and off and change colour to show a visual ranking of other users in the group based on their progress toward their goals. Users would be ranked on how close they were proportionate to their own goals to create a fair ranking. LEDs above the middle light would represent others who were doing better than the wearer. LEDs below the middle light would represent others who were not doing as well as the wearer.
Let’s assume, for example, that Alice is well progressed toward her goal. Bob isn’t doing as well. Carol has been very inactive and is the furthest of the three from her own goal. Alice’s middle light (her individual light) would show a mostly green indication. Below this light she would see a cyan light and a magenta light (representing Bob and Carol who aren’t doing as well as her).
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Bob would see a blue light above his middle light (representing Alice) and a magenta light below his middle light (representing Carol). Carol would see both Alice and Bob (represented by blue and cyan lights) above her middle light, showing she is least progressed toward her goal compared to the others in the group. Her individual light would be mostly red, showing her that, individually, she is far from her goal. (Figure 4.16)
In implementing this display I chose to limit the maximum number of users per group to five. With N = 5 users, N +N −1 = 9 LEDs in total would be required. This seemed a feasible number given the maximum size of a wrist-mounted device, and the desire to not have so many lights as to make the display overwhelming. A total ofN = 5 user colour codes would be needed, although onlyN−1 = 4 distinct colours would be displayed at once. This is possible using the primary (red, green, blue) and secondary (cyan, yellow, magenta) colours, and white. More users would require more unique colours, which may be difficult to create with RGB LEDs and may be hard for users to tell apart.
Note that for the purposes of ranking users within a group, the sliding window period used to calculate users’ activity averages need not be the same length as the windows used to calculate users’ goals or individual activity indications. A shorter window will tend to rank users on recent, short-term activity whereas a longer window will tend to rank users on consistent long-term activity.
This ranking approach has a number of advantages over the flashing notification used for the Activmon device. It reveals each user’s activity individually rather than anonymising them in a single indication. At a glance the wearer can see how group members are performing in relation to one another, as well as seeing where they are in relation to the group. If they are interested there is the opportunity to track other group members’ activity over a period of time.
This provides an element of social context for the wearer’s individual activity. It also enables social dynamics involving competition and co-operation between group
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members. If a group is made up of people who know one another, it is necessary for them to learn a mapping between people and their colour codes. However, even without knowing or remembering exactly who each colour represents, users can relate to them as individuals. Colour mappings are potentially easier to understand at a glance than positional mappings and do not require textual labelling.
There are potential downsides to this new group display. By moving away from a flashing notification, some of the immediacy of the group display is lost. The changing positions of the colours are less conspicuous than a single light that flashes at the wearer. Having said that, I was unable to determine in the Activmon study whether users were actually prompted to change their behaviour as a direct result of seeing the light flash. Arguably, if a user is already occupied with sedentary activity, they may not be willing to engage in physical activity even if they notice the light flash. A ranking display is potentially more useful as it provides a persistently visible measure of group performance without the annoyance of seeming to directly prompt users to engage in behaviour they are not primed to undertake.
Although the new display answers the fundamental question of “how active are others?” it still does not provide any specific information about the actual activity of any particular user. This was a conscious design decision—providing information that was too detailed might make the display harder to understand at a glance and confuse users. However, rather than deny this information to users if they wished to see it, I would propose that in future it could be provided through some other means such as a phone app or website. It was, however, outside the scope of this research.