Giving an unannounced writing assignment can work to salvage a class where discussion has sputtered and everyone is looking down at the table.

When students are given informal writing assignments with a very short deadline, they are forced to produce rough drafts.

About think-pieces:

Students understand and retain course material much better when they write copiously about it. We tend to think of learning as input and writing as output, but it also works the other way around. Learning is increased by "putting out"; writing causes input. Students won't take writing seriously till all faculty demand it. Writing needn't take any time away from course material. We can demand good writing without teaching it. The demand itself teaches much. Students won't write enough unless we assign more writing than we can comment on--or even read. There is no law against not reading what we make them write. Writing can have a powerful communal or social dimension; it doesn't have to feel solitary.

8 minutes of writing at the start of class to help students bring to mind their homework reading or lab work or previous lectures. 8minutes in mid class when things go dead--or to get students to think about an important question that has come up. 8 minutes at the end of class or lecture to get them to think about what's been discussed. 5 minutes at the end of class to write to us about what they learned that day: what was the main idea for them, what was going on for them during that class. Not only will this help them integrate and internalize the course material; it helps our teaching by showing us what's getting through and what isn't.

This is the name I give to writing that is a bit more thought out and worked over--but not yet an essay:

Think pieces are a productive and nonpunitive way to make students do the reading on time and come to class.

When students understand that they are being asked for two very different kinds of writing in the course, their essays get better because of their extensive practice with low stakes think pieces, and their low stakes writing gets more thoughtful when they experience it as practice for the high stakes essays (and relief from them too)

I find term papers involve maximum work and minimum learning.

Peer feedback or student response groups.

Professors who don't use writing prompts argue that an important part of scholarship is learning to raise questions that will yield a good academic argument

Whatever you decide, do note that a prompt-less writing assignment needs a good infrastructure in order to succeed

Consider what you want the assignment to do, in terms of the larger thematic goals of your course.

Consider what kinds of thinking you want students to do

your prompt should address the importance of context and suggest things that you want students to consider as they write

Provide context

Break the assignment down into specific tasks

Break the assignment down into specific questions

Craft each sentence carefully

Be clear about what you don't want

Be clear about the paper requirements

Try to write (or at least to outline) the assignment yourself

Discuss the assignment with the class