The brain has 2 kinds of memory: a long term memory where what we know is stored and a short term memory.
When we learn, information enters through visual and phonetic areas into the working area where it´s processed, related to previous knowledge and finally stored to long term memory.
There is a continuos enconding and retrival proccess going on all time, between working memory and long term memory.
Working memory has a very small capacity, it can only hold from 5 to 9 pieces of information at a time.
Working memory has also 2 substorage areas, one for visual information amd one for phonetic information. One way to strech working memory is to use both storage areas.
The practical application of this theory is that when making presentations you should use visuals (images, animations, videos) to facilitate the understanding, processing and final storage of the facts or concepts you want to transmit to the audience.
Most of us use PowerPoint to present and usually add text to the slides. Eventhough, limited short bulleted content can be of some help to learning, text goes into the memory using the phonetic channel so soon your speech and text on the slide overload the phonetic channel, but your visual channel is not fully used.
Every time we finish preparing a slide we should ask to ourselves at least 2 questions:
1) Which words in the text could be replaced or enhanced by a image.
2) What part of what I will be saying, can be enhanced with an image.
These questions will probably bring to your mind many images. So: How can we get the images we need?
Today it´s very easy to find images on the web using Google. The problem is we are usually not allowed to use these images without the permission of the author.
Following is a list of places where you can get images. Some free and some paid. (Many very inexpensive)
This list was originally posted by David Anderson at the "E-learning Heroes" blog.