http://www.mediaradar.org/mcdowell_kanin_credible.php links to an interview where McDowell admits to research into false rape reporting.  theforensicexaminer/Gross (used in article) cites the 1281 sample size number, and the link to how it is possible that some people misquoted 556 has been quoted as: 

The discrepancy in the size of the dataset can perhaps be explained by the wording in the CfMR article which implies that the 556 case dataset was an earlier study “cited” in McDowell’s 1985 paper, not the main subject of it. The difference in percentages between CfMR and mediaRADAR might be explained by CfMR citing McDowell correctly, while the 60% figure was obtained by someone just adding the 80 “false” cases to the 256 “inconclusive” ones and calling them all false. (http://www.feministcritics.org/blog/2009/04/20/claims-about-mcdowells-research-into-false-rape-allegations-are-not-credible-noh/)

 but the mcdowell section (here) didn't include a 60% claim.  It included the 45% claim. No reason to throw that out.  We should use the 1281 sample size. One reason that the study is often attributed to McDowell and Hibler is their 1987 book "Practical aspects of rape investigations" http://books.google.ca/books?id=iV398oA5DdsC&pg;=PA181&lpg;=PA181&dq;=charles+mcDowell+practical+rape+investigation&source;=bl&ots;=P2Yt9i_z6y&sig;=R-ezsxhzIw3KPJYGnybSBJp2BX8&hl;=en&sa;=X&ei;=0_59T8SGI6Xd0QGRoPTHDg&ved;=0CCsQ6AEwAQ#v=onepage&q;=charles%20mcDowell%20practical%20rape%20investigation&f;=false , and so likely published there.  Perhaps we should disprove the existance of this book, before claiming that an unused potentially wrong version of McDowell exists invalidates that mcdowell exists.