No. Research shows that line by line editing, which is very time consuming for the teacher, does not improve students' writing or eliminate errors in the next assignment. Teachers should look first at global issues:

  1. Does the paper adequately address the assignment and make a clear point or points?
  2. How could the organization be improved?
  3. Where is further development/proof/content needed?
  4. Has the student used appropriate and sufficient sources and documented accurately for the discipline?
  5. Where could transitions and coherence be improved? Only when the student has successfully addressed these issues should attention turn to grammar and mechanics. Rather than marking every error, the teacher might identify typical errors or place a check next to each line that contains an error.