Jeff Sauro talks about the one thing worse than the user failing to complete the task. Failing to complete the task, and thinking they'd been successful. So an important aspect to your usability testing - asking the participant to rate their confidence.
And this is crucial on University websites. The huge, disparate nature of web publishing in most institutions provides tons of opportunities to get the answer to a question from numerous sources. And if you look for long enough, you'll sometimes get different answers to the same question.
I've long used a confidence rating question in my sessions. What Sauro classifies as a "disaster" is alive and kicking on higher education websites.
Measuring User Interface Disasters - article by Jeff Sauro
And a related article about an equally often observed trait:
Do Users Fail A Task And Still Rate It As Easy? - article by Jeff Sauro