Posted by Beth Loring on Wed, Feb 03, 2010
Most medical device manufacturers now know that usability validation is required for both CE Mark and US FDA approval of medical devices. Usability testing is a specific type of user testing in which a trained moderator presents a representative user (nurse, radiology technologist, surgeon, or whomever) with a product or prototype and asks the user to perform tasks for which the device was designed. Although usability testing can (and should!) occur iteratively during the design process, a final validation test is required to show that users are able to operate the device safely in an actual or simulated use environment, and that any residual risks are mitigated.
Importantly, the quality of usability test results depends largely on the skill of the moderator and his or her ability to select the right tasks, determine the appropriate data to collect, and remain neutral and unbiased when interacting with users. In fact, moderators have three roles they must carefully balance: the Gracious Host, the Leader, and the Neutral Observer. Moderators also need to know how to handle situations in which a user fails a task, completes a task incorrectly without realizing it, or becomes frustrated, among other things. Moderating isn't easy; it takes skill and practice.
A couple of months ago I was invited by my friends at User Interface Engineering to present a virtual seminar (webinar) called "Effectively Moderating Usability Tests." During the webinar the audience submitted insightful questions, like:
- "What's the impact of using the same test participant more than once?"
- "What do you think is the maximum reasonable amount of time for a test session?"
- "If participants get off topic, how can you tell whether they don't understand the task or the user interface is unclear?"
These and other questions were answered in a follow-up podcast.
If you're creating your Usability Validation Plan, and have questions about when and how to conduct testing with users, feel free to reach out to me.