While working on a report on synchronous tools for my current employer, I found an article that was really well done. The article, entitled "E-Conferencing for Instruction: What Works?" was published in EDUCAUSE Quarterly and is accessible online at http://www.educause.edu/ir/library/pdf/eqm0646.pdf.
Anytime a new gadget or gizmo comes out and hits the market, people get excited and think that it is going to change the world, especially in education. Think of all the hype around podcasting, webconferencing and clickers for instance... But one thing is for sure, without a plan--including learning objectives and a set of relevant activities and assessments--a brain, and a little human emotion, you will not be able to leverage these technologies and turn them into effective delivery methods for learning. Table 1 on page 47 really illustrates that tools are opportunities for added value only approximately half of the time.
As an Instructional Designer, I work hard to ensure that instructors obtain the training needed to add value to all web-based and classroom training.