I, and a whole lot of other people, have researched and written about the importance of helping students connect new knowledge with their prior knowledge.

The Scientific American just reported on more research reinforcing that importance.

The studies focused on visual memory — remembering images — but is certainly applicable to information. It looked at two studies. Here is the end of the article, which gives a good overview of the results (You can read the article for more information — it’s fairly short):

These two separate experiments present a paradox: why are we capable of remembering such a massive number of images with great detail in some instances, and not even a few images after a couple of seconds in others? What determines whether an image is stored in long-term vs. short-term memory?

In a recent review, researchers at Harvard and MIT argue that the critical factor is how meaningful the remembered images are—whether the content of the images you see connects to pre-existing knowledge about them. In the Zhang & Luck experiment, you try to remember meaningless, unrelated colors, and so no connection with stored knowledge is made; it’s as if the white board is scrubbed clean before you get a chance to copy the scribbles into your notebook. But in the Konkle et al. experiment, you see images of recognizable scenes that you already have meaningful knowledge about—such as where the roller coaster is likely to be located relative to the ground. This prior knowledge changes how these images are processed, allowing thousands of them to be transferred from the whiteboard of short-term memory into the bank vault of long-term memory, where they are stored with remarkable detail.

Together, these experiments suggest why memories are not eliminated equally— indeed, some don’t seem to be eliminated at all. This might also explain why we’re so hopeless at remembering some things, and yet so awesome at remembering others.