Premack’s principle interprets an extremely common phononmenan: “You have to finish your vegetables (Low Frequency) before you can eat any icecream (High Frequency)” .
I found this term in a CHI 2010 paper. The authors design extra physical activity in video games and lure players to trade such activities for virtual benefits in the games. This is exactly obeying Premack’s principle.
It dawns on me that in researching how computer can change people’s behavior, one of the most fundamentals is adopting this principle. It is simple (even, say, trivial), but it truly works. And it is well grounded since last century.