John Medina's presentation about the science of good presentations
"There is a mismatch between current constructivist educational theory and practice during many presentations. A conference presenter can adopt an approach the opposite of espoused belief, and inflict many slides and bullet points at an increasingly passive audience. Advice on presentation techniques is also at odds with a constructivist approach. The purpose and value of conferences is in the conferring to seek feedback, to compare experiences and interpretations, to engage participants with the issues, to convince, and to evaluate one's own beliefs, yet many presentations do not address these desired outcomes. The COERSEA (context, outcomes, engagement, resources, support, evaluation, and alignment) model compliments current trends in online learning design and is a possible approach to presentations that is intended to engage participants in a shared learning experience. The model is adaptable to various topics and contexts and has been practiced by the authors on numerous occasions."
A good overview of tips and techniques to make good powerpoint presentations.