Poor: There is no clear principle of organization; most paragraphs are very long or very short for no obvious reason.
Audience/Genre
Excellent: The writer takes pains to accommodate to the audience and genre by adjusting word choice, style, and content. It is quite clear from the title and introduction who the intended reader would be.
Good: There is some attempt to address the specified audience, but the writer sometimes lapses into an alternate style (for example too academic for a newsletter).
Fair: The writer tends to forget the audience and simply write about the topic or develop the thesis; even when the genre isn’t an essay, the writer uses essay-like conventions or style. Some elements may show an awareness of genre, perhaps the title or paragraph length, but overall the language is general or the writer simply writes for the teacher.
Poor: The writer ignores the needs of the audience and the conventions of the genre.
Spelling
Excellent: No spelling errors.
Good: One or two spelling errors, but not of the type to make meaning obscure, and not of basic or common words. The error may be the result of the writer taking risks and trying new vocabulary. or it may be a common error that is not always recognized as such (for example "thru" for "through").
Fair: A few minor spelling errors (more than two) but not enough to harm the writer's ethos seriously or impede the reader's comprehension.
Poor: A major misspelling of important or common words, or a number of minor errors which interfere with easy reading or comprehension.
Punctuation, & Grammar
Excellent: Punctuation and grammar are appropriate to the audience and genre and in fact enhance the style. They conform to the conventions for edited American English, or, if they do not, the reason is rhetorical and stylistic. Errors may occur but are few and do not markedly distract the reader.
Good: Punctuation and grammar are appropriate to the audience and genre. They conform to the conventions for edited American English. Errors may occur but are few and do not markedly distract the reader.
Fair: Punctuation and grammar errors may occur but are few; while they occasionally distract the reader and cause less fluency, they do not detract from comprehension.
Poor: Errors occur frequently and mar the writer’s ethos and the reader’s comprehension. Reading is frequently interrupted by error. The writer has not proofread.
Usage*
Excellent: Usage is in accordance with edited American English and sounds right for the audience. There is no inappropriate use of slang or jargon. Words and expressions seem carefully selected for the genre and audience.
Good: Usage is in accordance with edited American English and sounds right for the audience and gene. There may be a few clichés included, but they are used correctly.
Fair: Usage is sometimes wrong, or too formal or informal for the audience and genre, but this does not impede comprehension.
Poor: Improper usage and errors in usage are frequent and mar the writer’s ethos and the reader’s comprehension.