First, focus on your users goals. The real goals are personal, not task related: I want to do my job as easily as possible, not be too bored, and not make too many mistakes or look stupid. Then there are business goals, for example I have to capture orders from customers. Keep both of these in mind - a program can meet the business goals but fail the personal goals, and it will be seen as clumsy, inefficient and frustrating.

Beware that the goals of different users and stakeholders may conflict. Consider an informative web site funded by advertising. Most users will just want to find what they re looking for as quickly as possible. The owners and sponsors will want to make sure that each user is exposed to an appropriate amount of advertising. You will have to balance these different goals.

Define the features supported by the user interface in terms of the business requirements and the user goals. Don t expect the user to understand the internals of the system, and avoid making the user express commands in terms of the system s structure. For example, allow the user to capture a new customer s details as a natural part of the order taking process, not a separate reference data maintenance process.

Avoid disrupting the flow of the user s work. Dialog boxes, message boxes, changes from one form to another all disrupt that flow, and an interface with fewer separate visible elements will...