I believe that a grade is less a reward for or a penalty against the student's intelligence than a reflexion of the student's proficiency to write clearly and persuasively a paper on a given topic. Organization and pertinence of ideas, as well as grammar and clarity, are among some the chief criteria I use in grading a paper. The student has demonstrated a mastery in writing clearly and organizing ideas methodically on a given topic. Ideas are not randomly thrown here and there but are complementary and cohesive elements of a well-organized paper. B. is above average.
Ideas flow well.
Grammatical errors are minimal. C. is for an average paper that complies with the topic assigned or chosen. The student has done just what I asked for. Grammar is fair and content is intelligible. D. is for a paper written with a level of grammatical errors that sometimes hinders the comprehension.