GUIDe – Testing
It pays to test the interaction and especially the data of the user interface as soon as the first design is ready and the designers have tested it themselves by simulating test cases (usage simulations).
User testing can be conducted by organizing usability tests, where users carry out test tasks independently. However, typically we prefer usability walkthroughs which are a lighter and more flexible testing method for user interface prototypes at the development stage. The walkthrough session is conducted by simulating a user interface prototype in a meeting with a few users.
The advantage of a walkthrough session is that testing can be arranged with very early development drafts and scarce resource. Additionally, the meeting allows the users, being experts in their work, to bring forth new aspects and exceptions about their workflows, thus allowing us to fill in possible gaps in the field studies. Usability tests, on the other hand, are better suited at the end of the design phase or as an additional verification method at the end of the implementation phase.
Because during testing, the user interface design and the functionality of the system are still in the form of drawings and screen sequences, the user interface can be revised quickly after testing. The objective is to minimize the number of testing iterations by using our simulation-based design method: when the user interface has been designed to support the use situations as well as possible, user testing usually does not produce big needs for change. Changes are mostly due to intuitiveness problems that may still be left in the user interface, and emergence of new use situations that, for some reason, were not found out earlier when use situations were researched.