I'm thinking about modelling. I'm thinking about learners creating rubrics, and about learners needing time to work with material that is easy for them at first, and then working up to material that is right at their instructional/learning/nudging level; I'm thinking about scaffolding.
When post-secondary students (pre-service teachers, perhaps) are examining pieces of writing to develop a list of criteria by which quality can be measured, they should start with samples of writing from younger writers, much younger at first, and then work with samples of writing closer in intellectual age to them, and so on and so forth until they are reading, critiquing, and having writing conferences with their own classmates. Good writing conference techniques may not have been used when they were students in elementary and secondary classrooms, so retraining should occur so that the same mistakes are not made when they are in a classroom with their own students.
When students are learning the groundrules for discussion in a classroom, they should at first discuss a text or other content that is simple, and then work up to a text or content that is more complex. I have seen this go wrong. Class discussions gone wrong are not a pretty sight, and they were bad enough to keep me from having them for many years. Small groups were not much better if students were not trained and given templates for their remarks.
For reading lessons, tudents can work with a really easy text, say, a children's picture book with minimal text, then a fable or fairy tale (not saying they are easy, but they are short and can be used to demonstrate certain strategies). Then students have guided practice, in a small group, perhaps, with a more complex text. Those who demonstrate understanding can practice the technique with their chosen independent reading text, while others benefit from some reteaching.
This can apply to listening: Have students listen to a children's story aloud, with no pictures. Guide them to listen to increasingly difficult material. Discuss the techniques they used. Show them some additional ways to focus, similar to reading strategies but without visual cues. Read aloud some short news stories. Work up to New York Times articles.
How does scaffolding work in other subjects? ELA is more process, far less content than most subjects taught in school. I am lost in a sea of wonderings; I'll have to talk to some colleagues.