How does the activity log work for a quiz and how should I interpret it?

The log will say "Stopped viewing the Canvas quiz-taking page..." and then when they resume. I told my students I could monitor their activity during an exam, so they should not leave the page, and several students have this flag in their activity log. However, I have since learned that if the cursor leaves the page (e.g., at the bottom control panel, etc.) , or email popups come across the screen, it could show this message. Often they "stop viewing" for a second or two and it may be a "glitch," but sometimes they resume 1–2 minutes later. Could they still be in the quiz and just thinking? 

#activity log