Since we are all doing it, we have no way of measuring in any scientific way how effective it is. The potential for creating teaching materials that are rich and deep has always been great. That is because education is such an exciting and challenging profession. The new optical electronic technologies with their capacity to store and play back massive amounts of material offer new horizons. But there are obstacles.
Cost is one.
On the other hand, with potential audiences around the world in millions, that should not be a problem. Another obstacle is educational practice. That is not to say they cannot be used in group and classroom situations. Our own Bodydisc and Living Arctic discs are used in this way in British classrooms. But access to large audiovisual databases and a lot of interactive materials will require changes in educational practice and style.