I teach middle school.
In my posted rubrics I always give the estimated time to do the project reasonably well. I give frequent reminders that I won't accept something slapped together in 15 minutes if the rubric says it should take 1 1/2 hours. Each time the rushers come back to me (often in 5 to 10-minute increments) I tell them it's starting to look better already, why should they hand in something so-so when they could hand in something great, etc. They say they "don't care"? I answer they don't have to care, they have to learn. And I make it clear that I, not they, decide if the work is finished.
Usually the project has improved enough to impress the student him/herself, and it's easier next project.
Hope this helps.
. One of my biggest challenges right now is that the kids work at such different paces. Some kids will whip through a project and finish it very quickly and DO NOT want to work on it anymore and other kids will work SO slow. The kids that finish early just want to talk to their friends and not do anything else. Does anyone have any ideas for me? I have tried extra credit sketches, reading a book, helping me clean around the room and things like that, but many times they put up a struggle. What works for junior high! kids? Marcia L.