World Politics

Research Notes

Improving Data Analysis in Political Science

Edward R. Tufte*

Students of politics use statistical and quantitative techniques to: summarize a large body of numbers into a small collection of typical values;

confirm (and perhaps sanctify) the results of the analysis by using tests of statistical significance that help protect against sampling and measurement error;

discover what's going on in their data and expose some new relationships; and

inform their audience what's going on in the data.

Assistant Professor of Politics at Princeton University. He is the editor of and a contributor to The Quantitative Analysis of Social Problems (1969), author of the forthcoming Data Analysis in Political Science (1970), and co-author of Size and Democracy (1970).

* I wish to thank Hayward Alker, Jr., Stanley Kelley, Jr., Gerald Kramer, John McCarthy, Susanne Mueller, Walter Murphy, Dennis Thompson, and John Tukey for their advice and criticism. I also thank Joseph Verbalis, who constructed the figures.