To determine how writers who differ in editing performance respond to operationally defined categories of errors in different kinds of written texts, a study asked novice and expert editors to correct and comment upon three kinds of error (consulting, intuiting, and comprehending) in two tasks (a self-written essay and three essays written by others) under two conditions (feedback on error location and no feedback). Subjects were chosen from two populations of undergraduate students who differed in their error-correction performance, yet were similar in age and educational level. The essay topic for the self-written essay directed subjects to describe a personal experience and to generalize on the basis of that experience. The standard essays were adapted from essays that originally had been written by incoming freshmen as placement exams, on similarly structured describe/generalize topics. Results showed that: the expert editors did not correct all errors in the tasks, even with feedback on error locus; they did not distinguish between matters of correctness and matters of style and taste and judgment; they did not operate entirely by a set of conventional rules for editing; and, proportionally, they were no better than were the novices in correcting errors in their own writing. (HOD)