Commentary by Dr. Whitesel: Communication researchers have long known that watchers will retain more of what a speaker is saying, if he or she writes writes something down in front of viewers. Audience retention increases when something is written done on a whiteboard or large tablet, rather than just projecting the words on a slide on a screen via PowerPoint, Keynote or ProPresenter. While interactive whiteboards even allow your written points to be preserved online, writing on a temporal tablet (non-electronic whiteboard, blackboard, etc.) will force the audience to watch more closely, to interact with you and to write down the points as you write them. This communication enhancement is equally effective onsite as well as online.
Do an online search and you find a myriad of products that can help almost any size church improve the retention of what is being preached/taught (see a few examples below).
A. Clear boards