When we think about the usability of a system, an important step is to define the users clearly. This helps in setting precise objectives for the design, as well as in making them measurable.
For example, suppose we are designing a calculator. The decision of what layout to use will depend largely on whom the device is intended for!
Is it for shopkeepers and home users who need to tally expenses and sales? Or is it for college students who need it for coursework? The questions of which features are must-haves, which are nice-to-haves and which are unnecessary; all have different answers based on which user profile you are targeting. Hence it is important (from the beginning of the development process!) to identify your target users.
Designers often use personas to define their target users. A persona is a realistic representation of the target user group. Personas have been long used in marketing to understand the psyche (and more specifically, the purchase drivers) of the different customer segments in the target market. Similarly, designers use personas to keep focussed on a representative user’s needs and wants throughout the entire development process, and also to make decisions and prioritize between various options.
[Personas]…are fictional characters that we create, and they serve as a reminder of who our users are. Like any good fiction, a well-made persona has its own story to tell. The more believable the story, the better representation the persona is of users; the more accurate the representation, the more likely our decisions will reflect the user’s needs…Ultimately, personas help us make the user’s needs more memorable throughout the process.
A persona is the design equivalent of a character sketch in theater – it is only by delving deep into the character that we can hope to do it justice. Similarly, a good persona helps to uncover the motivations of users and their needs which we plan to address.