Working in pairs (you and one other person) will design the user interface to a
new automated home lighting control system. The system, using existing wiring and existing
lights (i.e. customers will not need to invest in anything new but the control devise)
will control all the lights in a families home from just one control panel. Although there
eventually will be several models which will be marketed to larger homes, we will assume
that you will be working only on the model that controls a home consisting of two
bedrooms, a bathroom, a living room, a dining room, and a kitchen. The system will also
control the garage (or carport) lights and/or the lights on the outside of the home.
The system will be sold to middle-income homeowners for both new and existing homes.
The system will be very affordable and the marketing strategy will emphasize the
convenience, security, and energy savings of an automated lighting control system.
It is your assignment to create a user interface that is easy to use and intuitive for
users of all ages and computer experience. The stress here is on usability.
The physical size of the interface will be limited to a control that is 20cm in width
by 10cm in height and can be bolted to a wall. You can put what ever you want on this
space, buttons, led screens, knobs, touch screens, stylus pads, track balls, etc. However,
you may not use voice-controlled systems--they are unreliable and too expensive.
Some of the features that marketing wishes to incorporate include:
- Presenting the time lights come on and off for each individual room.
- Ability to dim or brighten lights based on how much natural light is sensed (each room
will have its own sensor) in the room.
- Ability to override the presets for a single day if someone is at home and doesn't want
the automated lighting system.
- Override the settings for a week or more when owners are on holiday.
- Other features are encouraged and should be included based on your user analysis.
Exactly what your final project should include:
Sequence: The project is divided into three separate parts (see below for
description), each of which should be completed before the next is started.
Page limits: Each of the three parts should take about two to three pages. This
is in addition to the sketches of your design, which are mandatory.
Strategy: Non-technical people, without any training will use this interface. If
your interface description covers ten pages, then it probably contains a number of
features that people do not need or will use too infrequently to make them worthwhile.
Make the interface as simple as possible.
Note: This is NOT a programming class and you should not need to write a
single line of code to complete this project. Your time is better spent speaking and
interviewing potential users to find out what they want in this system.
Part 1: Task and User Analysis
You will probably consider yourself a potential user of this system, but it's always
dangerous to rely on your own impressions. So you should interview at least two possible
users (four is preferable), from different households, to determine exactly
what features your system users wish to have. This is part of getting to know your
users before designing a system for them. Then you will write up the following:
- A description of the users you will interview in the last part (it is O.K. to ask them
in this part what features they would like in a system). At least 2 people but 4 is
prefered.
- The general characteristics you expect system users to have (age, education, etc.).
- A list of the basic functions the system will support.
Part 2: Initial Design and Cognitive Walkthrough
Produce an initial description of the interface and perform cognitive walkthroughs on
it using the scenarios of system usage you identify.
Write up:
- A description of three scenarios of system usage. For example, "The homeowner
arrives home to find all the necessary areas of the home lighted and set to appropriate
levels of brightness." These scenarios will be used in your task-centered design
efforts. They should be chosen to cover the most important functionality of the interface.
- A description of your initial interface design.
- A description outlining the correct path users should take to complete your scenario.
- A description of any problems discovered with the walkthroughs.
- A description of how you can alter your system to design out those problems.
Part 3: Thinking-Aloud Study and Final Design
Modify your design to correct the problems discovered by the cognitive walkthroughs.
Then do thinking-aloud studies with two potential users. Ask each user to accomplish one
(or more, if you have time) of the tasks defined in the scenarios for task-centered
design.
For example, you would first describe the "thinking-aloud" process to your
subject, and emphasize that you are testing your interface, not their ability. Then, if
you were using the scenario described above, you would present your user with a drawing or
cardboard mock-up of your design and say: "Imagine yourself having to modify the
lighting settings in living room, how would you go about doing that. Show me what you
would do using this lighting control system, and please let me know what you're thinking
as you work through the problem."
Revise your design to avoid any problems discovered in the
thinking-aloud studies.
Write up:
- A brief description of the thinking-aloud studies, with special attention to problems
they discovered.
- A description of your final interface design including a mock-up of it produced in a
computer program such as paint, or Corel Draw, or any number of other programs. The goal
here is to see what the interface would look like in if it were to be produced.
- The "design rational" --that is, your reasons for the important features of
your design. The reasons should generally refer to the scenarios you've used in
task-centered design.
