Statistics — in the service of science

24 Dec, 2014 at 09:50 | Posted in Statistics & Econometrics | Comments Off on Statistics — in the service of science

A chicken is an egg’s way of constructing another egg, and empirical research is a scientific theory’s way of uncovering the theory’s flaws.

ServicemanIt’s harder to make such clear statements about statistics or engineering or computer science, as these are essentially tools in the service of science rather than being the object of study themselves.

And there are fields where new paradigms don’t seem so apparent. Consider three areas with which I’m somewhat familiar: political science, psychology, and economics. In political science, I see persistent difficulties in integrating different perspectives coming from the studies of public opinion, institutions, and political maneuvering. It really feels like we’re not seeing the whole elephant at once. And I include my own research as an example of this incomplete perspective. Psychology seems to be undergoing a reforming process, in which various unsuccessful paradigms such as embodied cognition are being rejected, with no clear unification of the cognitive and behavioral approaches. Similarly in economics, although there it seems worse in that various incomplete perspectives are taken by their proponents as being all-encompassing …

How does statistics fit into all this? Statistics can (potentially) do a lot:
– Guidance in data collection and the assessment of measurements. And recall that “data collection” is not just about how to collect a random sample or assign treatments in an experiment; it also includes considerations of what to measure and how to measure it …
– Methods for calibrating variation by comparing to models of randomness. This is where I think that statistical significance and p-values fit in: not as a way to make scientific discoveries (“p less than .05 so we get published in the tabloids!”) but as a measuring stick when interpreting observed comparisons and variation.
– Tools for combining information. That to me is the most general way to think of “inference,” and it encompasses all sorts of things, from classical “iid” models to more complicated approaches …
– Methods for checking fit, for revealing the aspects of data that are not well explained by our models. To me this includes all of exploratory data analysis, which is about learning the unexpected …

Again, statistics is in the service of science, and I see statistics as a way of organizing science rather than as a way of making scientific discovery …

I think most of the real scientific heavy lifting is coming from existing substantive theories; the statistics is more of a way of rearranging the data or … of adjudicating between competing hypotheses or underlying models of reality.

Andrew Gelman

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