for early adopters than a product that majority consumers will configure
themselves. It’s also more complex for designers to communicate which
devices are doing what at each point.
Determining the right composition
For any service, there is often more than one possible suite of devices that
could be used to deliver the service. The decision as to which is most practical
will be influenced by the following factors. You may wish to prioritize, per
task, which devices are optimal for each task, acceptable for the task, or not
possible for this task.
What best fits the situation and context?
The most important consideration is what best fits the activity, situation and
user needs. Certain devices need to live in one place where only one function
is required, e.g. blind/window shade controllers or light switches. Others are
used in a context that places constraints on form factors and interaction
modalities. For example, climbers need their hands free, so delivering altitude,
weather and location information to a wrist top makes sense. Using a mobile
phone’s music controls while driving would be dangerous. Key functionality
should be mirrored on the car dashboard in a way that minimizes demands on
attention. Features that are essential to one device may be inessential or even
inappropriate for others.
The availability and reliability of the network connection is also key. If you
have a good reliable connection you can afford to centralize more
functionality, e.g. putting your irrigation system controls on a smartphone. If
not, and you can’t afford to lose access to functionality, you may need user
controls (and perhaps more onboard intelligence) in the edge devices.
Can you work with pre-existing devices?
What hardware can you assume your user base already has and is familiar with
using? For example, if users all have smartphones you can use these to handle
complex interactions, determine location and identity, and in some cases
handle local and internet connectivity.
Smartphones come with onboard sensors (such as accelerometers), which can
be used for tasks such as activity tracking without additional hardware.
However, custom form factors (such as wristbands) may provide a better