Engineering Te Ara
Usability Testing
Demolition of an old building
While this stage was highly technical, the focus of the work remained firmly on the user and usability. Usability of a site is strongly related to the extent to which a user's mental model matches and predicts the action of the software system.
A software system may be represented by three models: the Implementation Model, the User's Mental Model, and the Designer's Model. The Implementation or Programmer's Model is the way a system works from the programmer's perspective; the User's Mental Model describes the way a user perceives the system works; and the Designer's Model is the way the designer represents the programme to the user, including presentation and interactions.
The Design Model or interface determines the usability of the software by mediating the interaction between the user and the behavior of the system. To maximise usability, the interface designer hides the system model and indulges the user's mental models – a person doesn't need to understand how a new car is engineered to learn to drive it.
Poor system design places too many demands on users and forces them to adjust the way they work to accommodate the system. The result may be a minor frustration or inconvenience, but in complex systems, such as an airplane or a nuclear reactor, the results can be disastrous.
COP Outcome development and evaluation
Since mental models simplify reality, Te Ara's designers were challenged to simplify, simplify and simplify again. Their aim was to make the site's basic, most frequently used functions immediately apparent, while making its advanced functions less obvious. A good, uncluttered, interface that supports users' tasks fades into the background and allows users to work efficiently. In some ways, the designers' aim was to make their work invisible.
The concept of usability also includes learnability and retainability. A good interface allows users to build on prior knowledge and get started quickly and make progress immediately. In the past, the onus was on a user to learn how a software application worked. Today, it is up to system designers to analyse and capture user expectations and build these into their programmes. The 1966 encyclopedia didn't come with a 100-page user manual. Nor does Te Ara. (To help MCH staff built up their knowledge of how to run the site, Optimation participated in a programme of skills transfer, training and mentoring.)
As the work progressed, test subjects were given sets of tasks to perform that they were likely to want to achieve on the live website. After observing subjects completing the same set of tasks, it became clear that some aspects of the site worked well, while others caused enough people to struggle to warrant further refinement. As a result of this research, a prioritised list of improvements and enhancements were drawn up and put into place.
