Ideas
The ideas are the heart of the message, the content of the piece, the main theme, together with teh details that enrich and develop the theme.
Organization
The organization is the internal structure of a piece of writing, the thread of the central meaning, the logical and sometimes the intriguing pattern of ideas.
Voice
The voice is the heart and sou, the magic, the wit, along with the feeling and conviction of the individual writer coming out through the words.
Word Choice
Word choice is the rich, colorful, precise language that moves and enlightens the reader.
Sentence Fluency
Sentence Fluency is the rhythm and flow of the language, the sound of word patterns, the way in which the writing plays to the ear--not just to the eye.
Conventions
Conventions are the mechnical correctness of the pieces--spelling, grammar, and usage, paragraphing, use of capitals and puncutation.