From John Bean, Engaging Ideas
A summary should be directed toward imagined readers who have not read the article being summarized. The purpose of the summary is to give these persons a clear overview of the article’s main points. The criteria for a summary are
A six-point summary meets all the criteria. The writer understands the article thoroughly. The main points in the article appear in the summary with each point proportionately developed (the writer does not spend excessive time on one main point while neglecting others). The summary is as comprehensive as possible in the space allowed, and reads smoothly, with appropriate transitions between ideas. Sentences should be clear, without vagueness or ambiguity, and free of grammatical and mechanical errors.
A five-point summary is still very good, but weaker than a six summary in one area. It may have excellent accuracy and balance, but show occasional problems in sentence structure. Or it may be clearly written but be somewhat unbalanced or less comprehensive than a 6 summary, or show a minor misunderstanding of the article.
A four-point summary is good but not excellent. Typically, a four summary reveals a generally accurate understanding of the article, but will be noticeably weaker in the quality of writing than a five or six. Or it may be well written but over only part of the article being summarized.
A three-point summary must have strength in at least one area of competence, and it should still be good enough to convince the grader that the writer has understood the article fairly well. However, a three summary typically is not written well enough to convey an understanding of the article to someone who has not already read it. Typically, the sentence structure in a three summary is not sophisticated enough to convey the coordinate and subordinate relationships in the article.
A two-point summary is weak in all areas of competence, either because it is so poorly written that the reader cannot understand the content or because the content is inaccurate or seriously disorganized. However, a two summary convinces the reader that the writer has read the article and is struggling to understand it.
A one-point summary fails to meet any of the areas of competence.