Dwayne, Keep students attention by using a variety of media and resources. I might say go no more than 15-20 minutes without changing how you deliver the lesson. Less breaks, that would allow abot 20 different or alternating activities in a 4-hour period. Most students would keep focused if clkass was structured this way. Another method is to use small group discussion, or lab sessions, as these avoid passive sitting and listening, but require active thought and movement, which is bound to keep students focused. Barry Westling