During a design process of an interface, a designer should has a view of an potential user of the interface. There are some important factors to consider in developing a profile of a potential user.
- user’s work experience (kind of job, years of experience etc.)
- general computer experience (types of applications used etc.)
- specific computer experience (experience with hardware and specific operating system)
- experience with a kind of product we design
- experience with a similar products to this we design
Designers have to think “broadly” about users:
- don’t just consider people who are experts
- don’t limit yourself to the current or local market
- think about expansion, don’t limit too much a group of people who you develop a product for
- make your product easy to use for novices and experts
How many people should we include in a test? It was found that:
- about half of all major usability problems are detected with 3 participants
- 80% of usability problems are detected with between 4 and 5 participants
- 90% is detected with 10 participants
A typical usability test now includes 6 to 12 participants, which are divided into 2 or 3 subgroups.