User Interface Evaluation

Detailed evaluation of the human machine interface is an effective method for designing a better user experience. Modern web applications are expected to deliver a high degree of usability. User participation within the development process is essential to meet those expectations. To balance the developer’s perspective, proven methods such as workshops and usability tests are applied to ensure the necessary degree of user participation in interface development.

Interfaces, built at the MPDL are subject to evaluation. Main focus are all interfaces of the current PubMan solution. Evaluation of the User Interface Engineering team has different approaches: Usability Interviews and tests, GUI Workshops and software based evaluation.

Usability Interviews (Thinking Aloud)
Interface releases are tested together with potential users from institutes of the Max Planck Society. They perform tasks covering important application functionality. An interviewer tracks feedback and observes user interactions. All issues are noted down. The test result is accumulated if at least 8-11 interviews are performed. A summary is given at the end of the interview series which leads to measures and changes in the interface.

The following table shows what is needed to conduct an interview at an institute.

Setup

Usability interviews are conducted to discover, document and classify usability issues for


 * a specific release (e.g. PubMan 2.0.0.1)
 * a functional prototype
 * a prototype draft

Up to 8 interviews are usually sufficient to discover the main flaws of a GUI. The interviewer just provides tasks for his participant. The participant does all tasks on his own and should be encouraged to comment on his actions. It is not recommended for the interviewer to interfere in any form. If the participant gets stuck and there are important steps to follow, he gets a hint how to continue.

Interviews can be recorded optionally if participants agree. If a participant is not able to solve a task or step it will be noted as a fatal usability issue. For later interviews with a more standardized set of tasks the issues are to be classified in the following way:


 * 1) Fatal (Task could not be finished successfully or in a proper way)
 * 2) Serious (Task could not be finished on the first attempt or user performance is bad)
 * 3) Minor (The user hesitates, is not sure or does not feel comfortable with the flow)

For each interview the UIE team provides an interview outcome. The document contains all tasks, observation notes and comments of participants. Additionally the interviews collect demographic characteristics as well to prepare data needed for personas.

GUI Workshops


For GUI changes, enhancements or new GUIs interface drafts can be discussed and shaped together with potential users. The most problematic part is to get at least 6 people who are interested and skilled to take part in interface shaping directly.

Participants should know about basic interface controls and their mode of operation at the frontend. At the same time they need to have a clear understanding of available functionality.

UIE Workshops can help clarify


 * how users approach their tasks
 * how they expect the interface to behave
 * employed metaphors

Two kinds of workshops are applied if necessary:


 * 1) Card Sorting
 * 2) Wireframes

Setup

For each workshop the UIE team prepares a topic.

Software Based Evaluation
An open source heat map application has been installed to track user interactions along with their mouse actions. The results did not deliver the required quality of feedback and the solution was not extendible towards more dynamic interfaces. Software based evaluation is on hold since then.

Cognitive Walkthroughs
Cognitive walkthroughs are done collaterally according to all interface drafts and prototypes.