The Entertainment Software Association has delivered a letter of criticism to Dr Robert Kail, editor of Psychological Science - in which a study on videogame addiction was recently published, reporting that 8 per cent of 8 to 18 year-olds exhibited "pathological" patterns of gaming.
The publisher's trade body based its complaints on a recent blog post by ABC News' director of polling, Gary Langer, which called into doubt the study's claim that the results can be applied to the broader population with a sampling error of plus or minus 3 per cent.
According to Langer, the study - conducted by Professor Douglas Gentile - used data provided by Harris Interactive through an opt-in online survey, which itself said: "Because the sample is based on those who agreed to participate in the Harris Interactive panel, no estimates of theoretical sampling error can be calculated."
Gentile admitted error, commenting: "I'd assumed they had gathered the population initially as part of a random probability sample," adding: "I missed that when I was writing this up. That is an error then on my part."
Michael Gallagher, CEO of The ESA, wrote in his letter to Dr Kail: "The concern arises from the fact that the sample group for the study was not randomly chosen… It was a 'convenience' sample of individuals who agreed to participate in the survey.
"As you are likely aware, such a sample is not truly representative of a national population group. Thus the results cannot be projected onto the broader population of children in this country," he explained, adding: "And the sampling error of plus or minus 3 per cent that Dr Gentile cited in the study is also meaningless.
"Based on the public comments of both Dr Gentile and Harris Interactive, we are requesting that any references to the study in your publication and on your website, clarify the methodological flaws in Dr Gentile's study and inform your readers how those flaws affect the accuracy of the study."
Gallagher concluded: "I have no doubt that you value your publication's credibility and reputation. Therefore, I hope this clarification is made quickly so that future readers of your publication are informed that the claims made by Dr. Gentile are not supported by the survey he has based them on."