One way to measure success is based on Students’ Grades in Later Courses.
I can see some good:
My courses would stack up to others more equitably.
People wouldn’t be able to give wholesale good grades for poor work.
It would be a more reliable source of feedback than student evaluations, written in a semester when they are not happy with their grades.
On the other hand, I can also see some bad:
The proposal is to measure something that the instructor cannot control, not just how well the student learned, but how well they retained and applied what they learned.
In regards to the last part: Isn’t application a part of our job as teachers? I agree that we can lead that horse to water but we can’t make them drink (or not just simply spit the water back up, if I may be so bold as to completely overuse the analogy), but I think that one of my jobs as a teacher of writing is to help students apply and adapt what they have learned for other classes. I bristle at the accusation by other profs when they tell me I need to do a better job because the students’ writing in their class is awful, yes, but there should be some commonly held assumptions as to what a student should know and should know how to do when they leave X or Y class.
I can teach my students to write in my class. I can teach my students to apply what they learned in my class. I cannot make my students apply what they learned in my class in another class.
For example, I and my department teach MLA style sheet in freshman comp. In the first semester class they cannot pass if they do not follow MLA style. But in the second semester class, I have had a student who says they don’t know MLA style sheet, even though they were in an MLA class last semester and I know they learned it. How can I make them apply something that I know they learned but which they managed to “forget” over winter break?