As we have pointed out before, understanding the user is a pre-requisite of high quality interface design, whether online or offline. This means taking the time to find out what motivates typical user groups, what they expect from a given site or application, and how they prefer to work (or play). The alternative to proper user profiling is simply plucking an imaginary 'user' out of the air - usually to add weight to personal preferences or prejudices.
The latter situation often consists of a so-called expert dismissing design features because 'the user wouldn't like it', when he or she is really saying "I don't like it". This common reference to a single undefined 'user' conjures up amusing images of a God-like entity casting judgment on interfaces from on high. In the real world, as we know, things are a little more complex. If "the user" is frequently invoked but never defined, it may be time to rethink your usability strategy.
Of course, after profiling has taken place, or when talking in generalities, there is nothing wrong with 'the user' being used as a convenient shorthand. But during specific projects it is essential to think in terms of real people rather than abstracts. This approach creates both better design and makes usability more understandable, in concrete terms, for others involved in the development process.
For those undertaking user profiling work, the following initial pointers may be useful:
Remember that users are not a homogenous group
No site or application has one single group of users who share the same attributes. On the contrary, there are likely to be a number of distinct user types, each of which will have differing expectations and work patterns. Good interface design will cater for as many of these groups as possible, whilst of course reflecting the different priority the business may accord them.
Don't rely on 'second-hand' information
Information concerning user needs and requirements should come from the users themselves. Although product managers or market researchers may claim knowledge of what users want or need, this can often be skewed by demands from high profile customers or survey responses, neither of which are necessarily an accurate way to develop an understanding of the user base.
Think in terms of user goals
Try not to define users solely in terms of their relationship with the application or site. Instead think of their overall aims in terms of their job or tasks they wish to perform, and thus how the product can assist in meeting these goals. This will help in understanding what motivates a given user type, when and why they would use the product, and what features they would find helpful or irrelevant.
but remember the bigger picture
It is important to describe each user group not only in terms of the tasks they wish to complete, but also with regard to any other information that may be relevant. Some user groups may be highly computer literate, for example, whilst others are not. Those tasks commonly performed by the latter should be designed accordingly. Good user profiling will provide any such background information that could have a bearing on the final interface design.