Good interfaces ensure that the user can not go astray, by limiting the choices or by drawing on the acquired knowledge which the user possesses (Chapter 3). In addition the application of constraints, affordance and visibility can greatly improve the usability of a design (Chapter 4). These criteria are then amalgamated into user centred design.
Chapter 3 of Norman talks about different forms of knowledge representation. The more tangible forms of knowledge deal with the information the user can extract from the environment and from life experience. These experiences constrain our actions.
Chapter 4 of Norman describes a multitude of criteria one can use to impose constraints onto a system. These constraints perform their function by limiting the choices one can make, or by limiting the choices available to the user. Constraints impose cues which allow the user to assess the operation of the artifact. In addition, the visibility and affordances discussed in earlier seminars also provide clues to the use of an artifact. We say these constrain the system, to hopefully a small finite number of obvious choices.
Become familiar with how knowledge is represented, and how this knowledge can be used to better enhance the usability of an artifact. When dealing with artifacts, try to understand what knowledge must be represented to achieve good usability. Furthermore, identify constraints that the system imposes to restrict the selections to valid choices. Start by examining an existing GUI as directed in the submission section of this seminar.
Using one or more existing software based user interface from
anyone of the multitude of GUI systems. Keep the scope small
enough to ensure completion. Be prepared to discuss the
constraints, which are imposed to guide the user or at least help
the user stay on the correct path. When you attempted to use the
interface, what problems occurred and how could they be corrected
by the use of constraints (Physical,
Semantic, Cultural, Logical) or Knowledge
representation. For this exercise it would be best to
choose a poor interface rather then a good one. Be prepared to
discuss various types of knowledge representation. If you
find an interface with a unique type of representation be prepared
to show screen shots and explain this representation.
Marks will be awarded for presentation, preparation and participation in the discussion which exhibit emulsion into the subject matter. Students who do not come prepared can expect a low participation mark.