The more difficult the learning situation or content, the steeper the decline will be. As time progresses the drop follows the pattern indicated below for a 50-minute lecture. Some research suggests that there is a revival of the attention of students during the last few minutes of a lecture so that the pattern follows the normal pattern of task attention with a slight variation. Industry proved long ago that a break in workers' routines was usually followed by a resurgence of activity and that, after the break, the volume of production approached the original output. A brief rest, a break in the action or a change in activity will normally show a marked improvement in attention immediately following the change, leading a graph of attention level in a 50-minute lecture.
Attention also varies throughout the day, the week, and the semester.
The peak time of the day is usually around 9-11 a.m., hits a low right after lunch, revives in the early afternoon and then gradually declines. Tuesday and Wednesday are the better days with some attention problems on Monday and Friday. The semester has high and low periods due to fatigue, concentration on exams, periods before and after breaks, etc. Physical conditions must not be ignored. A hot stuffy room can negate the best material and the finest teaching techniques.