Twice this week I've found myself talking to students about how they deal with work that isn't worth their time or effort. As much as we teachers might hate to admit it, such work exists -- arguably, it's rampant across the curriculum. The work might have purposes for the person who assigned it, but in terms of advancing learning objectives for the students, it is useless. If I were a student, I wouldn't take an instructor's assertion that the work has a purpose from their perspective as enough of a reason to care about it. Shouldn't it count toward some goal more significant than "I can't get my A unless I do this," in order to motivate students to do quality work?
Decades ago, when I was a college student, I ran across this phrase in one of those lists of Murphy's Law-type maxims people used to compile (I actually think I had a page-a-day calendar of them): "A research project not worth doing is not worth doing well." That one has stuck with me. There's a grain of truth to it. Trying to make everything we do something of the highest quality is probably a terrible idea. There are plenty of endeavors where the ratio of reward to effort just doesn't justify doing your best. Effort is a limited resource. We have to apportion it where it will do the most good.
What makes us unwilling to to admit this, as teachers, is that we're allowing for the possibility that the work we assign might be deemed not worth doing well. Maybe that's a possibility we could take more seriously, though. Is the work in our classes worth doing for our students? Is it worth collecting and evaluating for us? If not both, then why would we expend an effort to do our part of it well?