Sometimes. But with writer's workshop we assess our students' application of skills on a daily basis. Here are some of the ways in which we assess:
1.       We plan interactive mini-lessons where students show us what they know
2.       We conduct daily writing conferences where we record anecdotal notes about our students' progress
3.       We save writing in folders and portfolios so progress can be observed and reported
4.       We examine sample writing or anchor papers with our students, thus determining what our students know and what skills we want to spend more time teaching
5.       We provide our students with rubrics and checklists so they can self-evaluate and build vision of success
 
One of my favorite quotes by Betty Hollas is:  "Assessment is not the end of the writing process, it is the bridge to revision." With writer's workshop we develop a community of writers who are always striving to learn more, to create writing that exceeds expectations.