Dear George,
If experienced and new staff are put together for a training session, then the biggest issue arrives at keeping the crowd engaged as - the experienced are already aware of the basics and you cannot directly start the advanced training as new staff is also present.
In such a scenario, to keep all involved - keep asking questions to the experienced staff in between your training so that they are engaged in answering and the new staff will also gain from their knowledge. You may even conduct a small oral quiz of subject basics for the experienced staff.
Reiterate the important points and highlight the key pointers to be noted, for the freshers.
Then slowly move towards advanced training, once all the participants reach to same level of subject knowledge.
