When you use slides, the audience's eyes go from you to the screen. If your slides consist entirely of text, reiterating what you say, you are overlaying speech dynamics with those of text. This can reinforce your ideas but remember you speak much slower than the audience can read from the screen. The audience will read far ahead and be impatiently waiting for you to catch up. You can keep contact with the audience by limiting the amount of text on each screen and actively adding your comments, questions, examples and anecdotes.
Word pictures add a graphic dimension to text.
They are more absorbing and thought provoking than sentences or lists. Word pictures consist of words plus arrows, lines, boxes and distinctive positions. They show relationships, develop abstract ideas, and map theories. Slides can be used by the speaker as a teleprompter. This is a welcome feature but care must be taken to avoid your voice changing from conversational to a reading drone.