If you want to try it, I will share a few mechanics.
- Tell the students about it in advance. Have a good conversation about why you’re asking this. Don’t catch anyone by surprise in an exam setting.
- Show the point value of each question on the exam.
- Put the bonus question on the last page so that you don’t see their answers while grading. You don’t want to be biased by their estimate, or have anyone think you might be.
- Word your bonus question unambiguously so that, when the test is out of 61 but the bonus is a percentage, you know for sure if a student’s estimate of 60 meant 60/61 or 60%.
- Set a wide enough error margin that a student’s bonus doesn’t depend on you being surgically precise in grading. You don’t want to be thinking, as you grade a 5-pointer, that the difference between 4 and 4.5 could affect their bonus.
- If, like me, you also like to award bonus marks when you see an answer that demonstrates exceptional mastery of a topic, above and beyond the call of duty, that complicates the metacognition bonus. Students can’t be expected to account for when we might suddenly give them more than 5 marks on a question allegedly worthy no more than 5. Grade on a spreadsheet, and compare their metacognition estimate to their performance pre-bonus. Add the bonuses on after sorting that out.
- Let me know if you develop a good way of reporting this to students. I do a lot of tiresome writing on test papers, explaining their bonus or lack thereof, or I do a lot of tiresome typing into the courseware management system.
No students hate it. Some students don’t “get it” but are happy to throw a guess on the page. To them it’s just a lottery ticket. A very few students feel badly about making an estimate; it seems to push some cultural buttons about begging for marks, or bragging. A lot of students get a kick out of it, and some admire it. In a math class or with sophisticated students, I might have a chat, late in the term, about different strategies for making the estimate.
Incidentally, anecdotally, I get far less pushback on grading of qualitative questions. Once a student has mulled over their answer to a 10-point essay question and concluded it’s really about 7 points worth… it’s hard for them to look me in the eyes and say they think it’s a 9.