The Importance of Grammar and Mechanics in Writing Assessment and Instruction: Evidence from Data Mining.

The current study examined relationships between expert human judgments of text quality and grammar and mechanical errors in student writing. A corpus of essays (N = 100) written by high school students in the W-Pal system was collected, coded for grammar and mechanical errors, and scored by expert human raters. Results revealed weak relations between grammar errors and holistic essay scores and stronger relations between mechanics and holistic...