The first of the five usability characteristics - EFFECTIVE.
Effectiveness is measured by the completeness and the accuracy with which the intended users achieve their specific goals. The typical characteristics of an effective user interface are:
- clear terminology - in the user's language and appropriate to the task
- good, comprehensible choices on screen
- easy navigation; alternate means of navigating to an outcome, in complex situations (unfamiliar domain)
- quality user assistance/instructions
ATM machine and Calculator are perhaps two greatest examples of an "effective" system user interface.
Few web examples of effective design:
The examples can continue to flow; but basically we need to appreciate the overlaps between various philosophical and practical dimensions of usability that are apparent in the examples. These are a blend of focusing on being effective, and striking some balance amongst other characteristics like useful, usable, findable, and so on.
Generally, usability and user-centered design is an iterative process and finding a balance between different characteristics for the specific design context is an important part of the user and task analysis. For sites and products that need to have greater emphasis on being effective, the iterative process should evaluate tasks for how accurately they are completed, and how often they produce errors.
More to continue as we move on to the second characteristic of usability in the next feature - Efficient.
