<p><a href="/nyone who has taught in the laboratory or taken a lab course realizes there are difficulties. These include: It is often difficult for everyone in the lab to see clearly. The instructor may not show the entire demonstration due to time or cost restrictions. A student's absence can impact the student's knowledge and any group effort. Activities cannot always be repeated. Activities can be dangerous, expensive, or require unavailable equipment.">nyone who has taught in the laboratory or taken a lab course realizes there are difficulties. These include: It is often difficult for everyone in the lab to see clearly. The instructor may not show the entire demonstration due to time or cost restrictions. A student's absence can impact the student's knowledge and any group effort. Activities cannot always be repeated. Activities can be dangerous, expensive, or require unavailable equipment.</a></p>