Homework is a “sticky” practice, but how sticky and where?

What's wrong with the following sentences written by Time reporter Kayla Webley?

Beginning July 1, students in the Los Angeles Unified School District will likely spend significantly less time on homework each week thanks to a new policy that says homework assignments can account for no more than 10% of a students' final grade…. With the bold move, L.A. Unified joins an increasing list of school districts nationwide who have placed limits on the amount of homework assigned to students so those kids can spend more time with their families, on extracurricular activities, sports and hobbies. [emphasis added]

Hint: Grade weighting and amount are different terms. Extra hint: find the actual language anywhere in the new LAUSD policy that limits the amount of homework assigned.

To her credit, Webley tried to find relevant research; unfortunately, the research she refers to is fairly general (Is homework good?) rather than focused (Which homework assignments work best?). But because homework is part of our common script for schools, and we have had repeated debates over the value of homework, the budding controversy over the LAUSD policy is quickly falling into the "homework: good/evil" dichotomy. 

More broadly, I wonder if all our social-science terms about sticky practices are too generalized (and here I am including Mary Metz's "real school" script, Tyack and Cuban's "grammar of schooling," political science "path dependency," and so forth–I've always wanted to read a snarky book titled Path Co-Dependent No More, but no one has written it). There's a smallish sociology literature on "institutional isomorphism," which is about how practices become widespread and normative, and the various terms for institutional practice stickiness, but the world is a messy place, and I suspect practice "stickiness" is more contingent than people assume. Local policy controversies strike me as a good vehicle for exploring this, because they pop up often precisely because changes try to "unstick" some practice. Sometimes the practices stick, and sometimes they don't… anyone want a dissertation?

Disclosure: I have an indirect connection to an LAUSD executive, and that gave me a heads-up on the story's existence.