Oh, also, I am sure I have seen the Butler study late last year, but I cannot be certain, it seems familiar so I may have skimmed it. I had not run across the Rohrer et al document before, so thanks for that. It confirms something I had been thinking for a while, repeated exposure coupled with strong incentives to succeed in testing situations are very important, in combination, to longer term retention. Repeated exposure to any material is going to have a longer residual impact, that is obvious. Repeated exposure to things that are entirely contextual can actually be dismissed as unimportant therefore of no longer term importance and are easily forgotten. A strong reason to remember, then regurgitate, information is very useful, and we can remember things for a very long time. I had a former student I had not seen for 5 years complain to me that he can still remember the trigonometry formulae we learned in that class and he recited them to prove it. Unbelievable, given that he was not what you would call a co-operative student!!! Yes, we did tests then too - but that does not explain why he was able to recall such knowledge. There is no reason for him to recall or use that information in his employment, chef, so why did he recall it?
That is what makes people so interesting for me, these little quirks in our makeup.