The strategy, as Ginsburg and Gal (1996) put it, is to "situate problem-solving tasks within familiar, meaningful, realistic contexts in order to facilitate transfer of learning," and a glance at most workbooks or textbooks for math instruction shows how widely this principle is accepted.
This seems so easy. What makes it hard to do? I will suggest some reasons and discuss each in turn.
As an instructor, I know I don’t understand some contexts that learners understand, and so I’m unwilling to work with or make up problems in these areas. I’m afraid I won’t be able to get the "right" answer, or that someone will ask me a question I can’t answer. I don’t trust my students who know about an area to be able to explain it to me or to other students who don’t know about it, so I like to be prepared with a back-up explanation. If the area is something that I am not familiar with, I feel lost and unwilling to take the risk. An example for me is sports statistics. I know there are acres of math in there somewhere—batting averages, win/loss ratios, salary caps, comparison of scoring records from former days with scoring stats from today, but it’s not my life, so I don’t feel comfortable working with it in math class.
For me to use this area of real life, I have to learn something new, maybe a lot of new things; if I decide to learn from my students, it’s going to be messy, with a lot of "not math" going on in the math class. Maybe I can learn some basics from a book or from a friend, outside of class, and then I’ll have to trust my students to help me through the hard parts. There’s that shared power structure again.