Writing is supposed to be creative and assigning grades to writing assignments deters creativity. Instead of grading assignments, allow students to re-write assignments and ask them to make improvements to their original work.
When grading essays, try to make brief comments on students papers. If a student gets a paper back with too much red ink, it deters them from making appropriate improvements. After making minor corrections on the paper, list three things that the student did well and list three things that the student could improve on.
You should praise the student by commenting on the three things they did well. Praise increases motivation and a student can then recognize what they do well in their writing. The three tips for improvement then gives student the opportunity to see ways that they could improve their writing without being overwhelmed by being told everything they did wrong.
This technique saves time on grading, encourages students to improve and gives students direction. If you are interested in improving your students’ writing abilities, try this instead of giving a number grade. Evaluate their progress on improvement and not by comparing their work with other students. Do this and you will improve every students writing ability.