Scientific presentations for persuading smaller audiences (details, interaction, no distractions) requires a Conference Room style presentation. Conference Room style presentations tend to contain lots of details on each slide, the slides are mostly printed, not projected, and every slide must pass the squint test. The squint test is ensuring that your slide or hand out reinforces its main message. This can result in overcrowded but useful slides. So sciencetific presentations make mostly use of slideuments or documents, hand outs.
This video with Garr Reynolds form Presentation Zen and Nancy Duarte from slide:ology demonstrates the differences between ballroom presentations and scientific presentations. They also show the use of both for a small audience, good video.
You can also read about the distintions in a downloadable pdf