Dubious minutes indicate sessions of poor training. This article will explain the three reasons minutes are marked dubious.
When a session is marked as sandbagging, the student was inactive three or more times during their training. For more information, please read this article on sandbagging.
Very Low Accuracy
Very low accuracy is usually a sign that the student is training without paying attention to their work. Poor accuracy is often accompanied by review times of 10 seconds or less. We mark sessions as dubious if the student's session accuracy is below 20%.