Standard scholarly practice dictates the assembly of a literature review as part of any published study, and meta-analyses, as they gather together the findings of multiple studies, are particularly critical to literature reviews. That Groseclose and Milyo overlooked not only the Journal of Communication meta-analysis, but also the 59 studies it surveyed, raises questions about the seriousness with which they conducted this study.This is relevant because the promotion of this book is going to rest on the idea that it's a serious, objective, scholarly work. Yet in addition to ignoring the dozens of studies on media bias in the apparent belief that they were the first ones to ever attempt to address the topic quantitatively, Groseclose and his co-author used the most bizarre methodology I've ever encountered to come up with their assertion of liberal bias. See if you can follow: They took members of Congress' ideology scores from Americans for Democratic Action; searched the Congressional Record to see which think tanks each member cited in floor speeches; assigned ideological scores to each think tank based on who cited them on the floor; then counted how often the think tanks were quoted in news sources. If a news outlet quoted think tanks cited more often by liberal members, the outlet had "liberal bias." That's it.Anyone two weeks into their introductory research methods class can see the multiple ways this is destined to produce unreliable results. To take just one: do members of Congress actually cite only think tanks that cohere with their ideologies? Turns out, according to Groseclose's own data, the answer is no. According to their system, the RAND Corporation and the Council on Foreign Relations are liberal organizations (because they're cited more often by liberals), but the ACLU is a conservative organization (because it's cited more often by conservatives). So if a newspaper quotes representatives of RAND and CFR more than the ACLU, it has "liberal bias." I kid you not. With a coding scheme this strange, you get strange results. To wit: according to Groseclose, the most liberally biased major news organization in America is...the Wall Street Journal. When your method produces results telling that the Journal is the most liberally biased news organization, or that RAND is more liberal than the ACLU, the logical response is to reexamine your method and assess whether you're measuring what you think you are. But maybe not, if it's serving your ideological ends.The blurbs for Left Turn include an unfortunate one by the ordinarily smart economist/blogger Tyler Cowen, who calls Groseclose "the leading academic scholar in the area," which is kind of like calling me the leading academic scholar in the area of particle physics, since I once wrote a blog post that mentioned atoms. Maybe this new book revisits the glaring weaknesses of Groseclose's prior work, and he performed a whole new set of studies improving on the last one. But since his CV lists, on the topic of media, only the Quarterly Journal of Economics study and one essay in Critical Review that essentially describes the former study, it seems unlikely. Groseclose hasn't published anything on the subject in a peer-reviewed journal since. Sorry about this long-winded post, but the point is this: in a few weeks, Tim Groseclose is going to be all over Fox News, conservative talk radio, conservative magazines, and conservative blogs, talking about his new book that proves how much liberal bias there is in the media. He's going to be celebrated by conservatives because he supposedly lends "scholarly" imprimatur to what they already believe. If the past is any indication, it'll be almost completely bogus.Indeed, they seem to be unaware that an academic discipline of media studies even exists. Their bibliography includes works by right-wing media critics such as Media Research Center founder and president L. Brent Bozell III and Accuracy in Media founder Reed Irvine (now deceased), as well as an article from the right-wing website WorldNetDaily. But Groseclose and Milyo failed to cite a single entry from any of the dozens of respected scholarly journals of communication and media studies in which media bias is a relatively frequent topic of inquiry -- nothing from Journal of Communication,Communication Research, Journalism and Mass Communication Quarterly, Journal of Broadcasting & Electronic Media, Political Communication, or any other media studies journal.