Where's the beef? A comment on Ferguson and Donnellan (2014).

APA NLM tapraid5/z2p-devpsy/z2p-devpsy/z2p00114/z2p3285d14z xppws Sϭ1 10/28/13 1:33 Art: 2013-2619 Developmental Psychology 2013, Vol. 50, No. 1, 000 © 2013 American Psychological Association 0012-1649/13/$12.00 DOI: 10.1037/a0035087 COMMENT Where’s the Beef? A Commentary on Ferguson and Donnellan Frederick J. Zimmerman This document is copyrighted by the American Psychological Association or one of its allied publishers. This article is intended solely for the personal use of the individual user and is not to be disseminated broadly. AQ: au University of California, Los Angeles To make a scientific contribution, a reanalysis must be firmly rooted in the identification of a clearly superior methodological innovation over the original research. By contrast, a reanalysis rooted in dissatisfaction with previous results will necessarily be biased and can only obscure scientific discov- eries. The reanalysis published by Ferguson and Donnellan began with a highly selective literature review, failed to justify its methodological choices, and interpreted its results in an incautious way. Notwithstanding these problems, the Ferguson and Donnellan article leaves intact the core contributions of the original article: that there is no evidence of a positive effect of infant viewing on subsequent development and that it is well worth conducting more research on the effects—including potentially adverse effects— of infant TV, DVD, and video viewing. Keywords: mass media, television, language development, child development, reanalysis such, the results would have been published whether they had shown a positive association or a negative association. Ferguson and Donnellan went on to cite an article claiming that “almost all articles . . . in the behavioral sciences publish results which confirm the a priori hypotheses of the authors” (p. XXX). How- ever, the original study that they reanalyzed had no a priori hypothesis. Thus, as a descriptive study in an understudied area, the article was not a good candidate for charges of publication bias. The reasons for this reanalysis, thus, are murky, and the reader would have been better served by a clear-cut rationale for con- ducting the reanalysis. Ferguson and Donnellan appeared to be more concerned with the negative findings. In their introduction, they claimed that “other research fails to support a clear negative association be- tween media exposure and cognitive outcomes” (p. XXX) and cited three articles, all of which, indeed, failed to find a clear negative association. Yet these three articles in turn cited other research studies, not cited by Ferguson and Donnellan, that did show negative associations. These articles included three experi- mental studies finding a negative association of TV viewing and language development (Carew & Clarke-Stewart, 1980; Gottfried, 1984; Nelson, 1973), a case-control study that found language delays with early viewing (Chonchaiya & Pruksananonda, 2008), and a longitudinal analysis that tested the effects of different content on cognitive development, finding negative effects for violent content and no effects for educational content (Zimmerman & Christakis, 2007). Much has changed since the original article was published. More is now known about causal pathways and why a negative association between television and language development might occur. Language development depends crucially on parent– child interaction (Zimmerman et al., 2009) and even on play (Christakis, Zimmerman, & Garrison, 2007), both of which television seems to displace (Christakis et al., 2009; Schmidt, Pempek, Kirkorian, Lund, & Anderson, 2008). In addition, other work in this area has The garden of science has many useful species: theoretical modeling, descriptive studies, tests of hypotheses using observa- tional data, natural experiments, randomized trials, meta-analyses, and so on. To this richly productive ecosystem, Ferguson and Donnellan proposed to contribute a reanalysis. While a well- conducted reanalysis motivated by clear methodological improve- ments can enhance scientific understanding of an issue, the reanal- ysis offered by Ferguson and Donnellan fell well short of the ideal in its introduction, its methodological choices, and its interpreta- tion. The result was a reanalysis that produced more heat than light. Motivation The article by Christopher Ferguson and Brent Donnellan pro- posed a reanalysis of an article published in 2007 (Zimmerman, Christakis, & Meltzoff, 2007a) that presented results of a survey of parents of children ages 2–24 months. One motivation for the reanalysis was concern over possible publication bias, with the implication that the original article might not have been published had the results been different. How credible is this claim? The original article noted that concrete claims had repeatedly been made on behalf of the effectiveness of baby videos in pro- moting child development, and yet no research had at that point been conducted that would support those claims. The purpose of the original article was to contribute some correlational evidence about the face value of those marketing claims. This article became notable because it addressed an issue not previously studied. As Correspondence concerning this article should be addressed to Frederick J. Zimmerman, Department of Health Policy & Management, Fielding School of Public Health, University of California, Los Angeles, Box 1772, Los Angeles, CA 90095-1772. E-mail: fredzimmerman@ucla.edu AQ: 1 AQ: 2