Lane was worried that her students would become discouraged if they saw a lot of mistakes marked on their papers. So to help them develop confidence in their writing skills, for the first essays that they turned in at the beginning of each term, she was very selective about which mistakes she marked. Thus, their first grades were all relatively high. Unfortunately, this approach had some less-than-desirable outcomes, not only for her students, but also for their teachers at the next level.
First of all, the message to the students was, “You don’t have to carefully edit—you can still get a good grade.”
Also, as the term progressed, she realized that several of the students were still making many mistakes, whether from poor editing and/or from lack of knowledge. At the end of the term, she had to decide to either fail those students, which would be a shock to them since they wouldn’t be expecting that, or pass them, which would be a burden for their next teacher, who would have to deal with students who didn’t have the skills necessary to be successful at that level.
A better approach has been to mark every mistake as long as the teacher is strategic when dealing with essays.
Common Sense Teaching ESL 