I think Tony Buzan did some study saying that the reason 30 minute chunks work so well:
In something a like a 3 hours study session the attention span was relatively high for the first 15 minutes, then dropped tremendously for the rest of the period, until 15 minutes before someone finished, knowing that that would be finishing up. He found that the best approach is to go for 30 minutes, then break for 20, then do another 30 minutes, because 15 minutes in your attention is great, and the 15 minutes out it's still great. But he conditioned that during the 20 minute break, you can't be taking in information, so no TV, no pleasure reading, and to an extent, not really talking to anyone or listening to music: minimal information retrieval. He said, instead, to daydream or fantasize for those 20 minutes while your brain processes the info. While I was learning PRing, I felt some credibility in everything since everything seemed to reflect Buzan's study. Plus, he like invented mindmaps or something (despite what the PRing package in the book said, in that sample article to photoread about some girl who came up with it; I think the article even mentions Buzan's book. This isn't a blow to LSC, it was the sample article).
"Come along, and ride in a Fantastic-SLIDE SLIDE, DO-RIDE..."
-Ramon http://razor.ramon.com (website still down because Coolio hacked the netidentiy server with his dreads and said, "Y'allz gotsta respect el CooliO!")
