One recent evening I had the opportunity to listen as a panel of college writing professors discussed various aspects of their job – from generating interest in writing to grading to syllabus creation.
The panel spent several minutes discussing the question of where to focus beginning writers – on quantity or quality. One of the panelists stated without opposition that the focus for beginning writers must be on process and production over, but not to the exclusion of, revision.

The beginning writer should not be concerned with finding a high concept (a “great idea”) and executing it, or achieving perfection by the end of the semester on a ten-page short story or a set of three poems. Make either of these a focus – or allow the student to – and then he or she will not gain the foundation for craft but will instead develop the false concept that writing a story or poem or essay is simply another problem to be solved (like solving an algebraic equation or calculating molecular weight).
One teacher wisely has students write in volume – as much as 40,000 words over a two-semester freshman year seminar (FYS). This accomplishes two things. First, the student is a better writer at the end of that year than they were at the start. Indeed, this is inevitable for anyone who writes so many words in a year. Second, their relationship to writing is changed. It is no longer intimidating to stare at a blank page. Any mental blocks that suggest to the student that they are not a writer or that they lack “material” are eliminated. Essentially, this quantity-based approach makes a writer of the student, a collegiate who sees the value of writing as a cross-disciplinary skill.
Revision of a single piece remains important and is not to be abandoned. Revision allows the student to apply instruction, especially comments written on their paper by a professor.
Part of this mass of writing should be spent in a revision or two of a couple of pieces. However, most of the writing should be either in response to reading (a perfect alternative to the quiz) or in discovery writing – writing not to produce a fully faceted piece but to understand better some idea or observation.
By design this writing is done every day, or at least three times a week. This creates an opportunity for the beginning writer to see how scheduled and disciplined work acts as an engine for productivity.

Inside or outside the classroom everyone in the writing world sees it as fact – writing as often and as much as you can is the sole route to successful practice of the craft. Quantity is the sole route to quality*.

*If you end up talking with someone that doesn’t agree on this point, you can presume they don’t write on a regular basis, if at all. They are either a reader or a weekend writer – their writing is a hobby. Ask them how often they write, ask them about their process. This will clear it up.