Matching of normally oriented and mirrored words by good and poor readers

10 good and 10 poor Grade 6 readers judged tachistoscopically presented word pairs to be "same" or "different" when the words making up the pairs were both normally oriented, both mirrored, or one was oriented and the other was mirrored. Good readers made fewer errors than poor readers on normally oriented "same" pairs but showed no advantage on other configurations. Poor readers were more accurate in detecting mismatches than good readers. These results were discussed in terms of the mechanism that may have been implicated.