Date: Mon, 9 Mar 1998 15:41:58 -0500 Subject: BHA: Realist MethodsThanks Andy and Howard for your responses to my post. Andy, First, let me say that I am no methods expert but as I have just finished running scores of statistical tests -- including multiple regressions -- on our new welfare legislation, I hope I am not an inconsistent realist. I still don't think I am. I also apologize, Andy, if my reply was somewhat confusing because I was also replying not to what you had said but what others had said. I think that applies to the point about chi-square. I, too, think the issues raised are important for us to collectively clarify. For my part, I do not think that Bhaskar is committed to the view that empirical regularities are very rare -- not empirical regularities per se. If Bhaskar is committed to that claim, then, it seems to me, he is obviously wrong. There are many empirical regularities. The sun rising every 24 hours, all sorts of tendencies associated with demographics, etc. What Bhaskar is committed to, I think, is the view that in an open system, there are no _invariant_ regularities -- nor even statistical regularities with invariant probabilities associated with them. Yet, it is such invariances that are needed for regularities to support explanations conforming to the covering law model. With regard to regularities of this form, I think Bhaskar is totally correct: They are rare if they exist at all and do not in any case constitute an explanation. Invariant regularities can be contrived in closed systems. We construct a micro-world in which only certain mechanisms operate without interference so that what they produce is invariantly regular. But in open systems, regularities occur too. They are just not invariant regularities. But it is on that quality of invariance that positivism rests. It is crucial. I am intrigued by the account of multiple regression that you and others have advanced. I agree that in multiple regression, we are examining the contribution of each independent variable on the dependent variable, controlling for all other independent variables in the equation. Although I have never thought about this in these terms before, my initial response is to disagree that the effects of those controlled variables are non-actual. In fact, what the regression equation is controlling, it seems to me, is precisely the actual effects of the controlled variables. If there were no actual effects of these variables, the regression equation would not pick them up. Insofar as the regression equation does pick them up, they are not only actual but empirical as well. Think of this in terms of vector forces. The regularity or non-regularity that results at the zero-order level is due not just to the independent variable but as well to the vector sum of all those other forces operating simultaneously. Since they are operating, they are actual. What is _not_ actual, perhaps, is the regularity that would have resulted were those actual effects not operative. The real, non-actual effect is what the regression equation displays. So it isn't the effects of the controlled variables that is non-actual but the regularity that would have resulted from the isolated effect of the independent variable of interest. In the kind of analysis I've just been running, I want to see if there is a relationship (a regularity) between the cut-off of welfare and quality of life. Any bivariate statistical test, including zero-order regression, tells me that. Then, I want to see if this is a real effect or a spurious correlation. To test this, I use multiple regression or two-way ANOVAs, etc. But the bivariate relationship is still important to establish first. No bivariate relationship established, however, will be invariant. It can be counteracted or mitigated just as we know. And, I say again, the statistical relationship is not the explanation but only evidence for an explanation. I am not familiar with the criticism of regression that Hans raises, but it does not seem to me a critique distinctive to a realist point of view. As you suggest, it is a criticism that even positivists would acknowledge. My own realist response to those criticisms is to acknowledge their merit and the fallibility of all knowledge and techniques and to ask what alternative technique works better. I think Hans mentioned something, but I don't think we in sociology are very familiar with it. Thanks again, Andy, for the comments. doug --- from list bhaskar-AT-lists.village.virginia.edu ---