When we come back together as a group, my job is to fill in the gaps and clarify their answers for the whole group. Of course, the hidden lesson is that people hear other views on safety issues which may not be the ones they hold. It causes them to think about their actions and what they believe, and often results in heated discussion and behavior changes. Interaction among employees, confirmatory statements, or testimonials are excellent for getting people involved and to possibly adopt a change in behavior. You can be specific and focused on the training need, and generally spend less time training since you do not get bogged down in background information.
Flexibility is again the key.
But, talk to your employees to determine their needs. I don't believe there are many laboratories or veterinary areas at CDC that do not have a computer for people to use. CBT is slowly moving into the workplace to provide training directly at the employees desk. It's advantages are that nearly everyone has access to a computer which can provide access to training programs 24 hours a day. Plus, employees can go through the training at their own pace - advancing when they have completed material and reviewing material as needed before they go on to the next section.