here are some of the findings from my analyses of the various "experiments" done over at d.p. the best proofers miss between 5% and 25% of the errors over the course of proofing an entire book. the worst proofers miss an even higher percentage, but it is not all that much higher, probably 10-40%. there is no evidence for the position that proofers "get bored" and therefore miss a higher percentage if the text they proof is clean (i.e., has few errors)... p3 proofers are no better than p2 or p1 proofers. some errors withstood over 5 rounds of proofing; there was nothing obviously "difficult" about them. the best predictor of whether a page is now "clean" is how many people proof it without finding an error. if the last person to proof a page found an error, then you cannot reliably predict it to be error-free, no matter how confident the proofer believes that... if anyone wants to dispute or discuss these findings, i'd be open, and will ask about your supportive data. -bowerbird