(FORTUNE Magazine) – Why do we have this eerie feeling that Times Mirror, publisher of the Los Angeles Times and other papers, has switched the deck on us? Answer to that question, generated by four seconds of introspection: because they have so switched. They have now gone and published a study of public attitudes toward the media, and if you look at the number of people they interviewed, the eminence of the survey designers, and the glossiness of the paper on which the results have been published, you would have to say that this is very high- class polling indeed. But golly, fellows, if the big issue is the ''credibility'' of the media, you do not resolve it by asking Mr. and Ms. Public whether they think that ''in general . . . news organizations get the facts straight.'' Of course, they get the facts straight in general. And of course, if you nice liberal folks at the Times Mirror suggest that factual accuracy is what it's all about, then you will indeed get a landslide vote, with news organizations receiving credibility ratings of 80% to 90%, and with various dissonant noises elsewhere in the survey data made to seem like minor matters. But take it from us, fellows, the real credibility issue lies elsewhere. The real issue concerns bias about what does and doesn't get reported, not the factual accuracy of the reports. And the survey data -- to cite a detail that few news stories about them got into the lead -- show that people brood a lot about bias. A majority of those who had an opinion believe the press is biased, and most of that majority thinks the bias is liberal. So why didn't some of you fellows at Times Mirror structure the survey to emphasize this point? And why do we have an eerie feeling that the question has already been answered?