Look for positive responses from students. If certain methods or techniques elicit active student participation and interest, other teachers should employ those methods. Much of what classroom training evaluations ultimately seek to find is that students learn, so you can use their engagement as a gauge for making your evaluation.
Make sure the teacher doing the classroom training is aware of all that is expected of her. The evaluation will be unfair if you judge her on criteria she does not know she is responsible for. Supplying pamphlets, guidebooks, or manuals are ways you can direct teachers to inform themselves about pertinent protocol and standards. You can also hold meetings to inform them of what you will be looking for.
Evaluate surreptitiously if possible. If the person whom you evaluate knows you are evaluating her, she may act differently that she otherwise would. Students, too, may be less tempted to feign interest and participation if they do not know you are there.
Inform the teacher of the goals of the evaluation. It could be that the evaluation serves to assess student learning skills or it could be an evaluation that gathers data on a teacher for an award. If you tell the teacher the purpose of the evaluation, she can spend time making improvements and adjustments to her teaching style.
Let the participants in the classroom training evaluate themselves. Make sure that when they evaluate themselves that they have no knowledge of the findings in your evaluation. You can then compare the evaluations to see if there are discrepancies or gaps between the two. If you do find gaps, you can use these gaps as potential areas for improvement.