Christianity Today has an article on the effects of short term missions which basically equates to “not much.”

The participants don’t have life changing experiences and neither do the folks they go to work with.

I have to say that if short term missions means a week or two, then yes, most likely I think this is true. If by short term missions they mean a summer, a year, or two, then I think it is not. I think that longer terms of service have more impact on your life. I was on a short term mission for 16 months. That has changed my life.

found via Smart Christian