User-centred design
User-centred Design (UCD) is both a philosophy and a process. It places the person, as opposed to the 'thing', at the centre of the design process. It is a process that focuses on cognitive factors, such as perception, memory and learning, as they relate to peoples' interactions with things.
For UCD the first stage of design is to understand the users, the tasks the are seeking to perform and the environment in which they work. These findings contribute to the development and design of the product.
Rather than approach software development from a classic waterfall model, UCD seeks to implement a highly iterative approach with the users involved at every stage. The stages progress from design to prototyping to user testing and evaluation and then back to design. Each phase has an impact on the following phase.
Evaluation of the interface is one of the key aspects of UCD. Two approaches to this evaluation are:
- User observation
A user is observed working with the interface to perform an identified series of tasks. Measures could be taken for how fast something can be done, or how many errors are made or could be more qualitative and explore how the user feels about the interface.
- Heuristic evaluation
An inspector assesses the interface to determine if it conforms to a specified series of design principles. This can be a quick and effective method to be used before more in-depth studies.