Political Scientists" Role - NYTimes.com Jacqueline Stevens ("Political Scientists Are Lousy Forecasters," Sunday Review, June 24) attacks a claim that few political scientists make. Forecasting is a very specialized field in political science, limited to predicting election outcomes, and the record in that field is impressive. But that is not what most political scientists do. Political science, like most social sciences, seeks explanation rather than prediction. Its aim is to explain puzzling phenomena by relating them to phenomena that are well understood. Much of science consists of trying to resolve puzzles in that way. This effort deserves public support in the field of political science as much as it does in the field of economics or, indeed, high energy physics. In the long run, our ability to resolve puzzles contributes to the survival of our civilization even if in the short run it does not help us predict what will happen tomorrow. The writer is professor emeritus of political science at the University of Iowa.