Privacy Indexes:
A Survey of Westin’s Studies

Ponnurangam Kumaraguru, Lorrie Faith Cranor

CMU-ISRI-5-138
December 2005

Institute for Software Research International
School of Computer Science
Carnegie Mellon University
Pittsburgh, PA 15213-3890

Abstract

Since the late 1970’s Dr. Alan Westin has conducted over 30 privacy surveys. For each of his
surveys, Westin has created one or more Privacy Indexes to summarize his results and to show
trends in privacy concerns. Many privacy researchers are interested in using these privacy indexes
as benchmarks to which they can compare their own survey results. However, the details of how
the indexes were calculated have not been reported except in the original survey reports. These
reports were originally distributed in paper form, and many are no longer readily available. We
obtained paper copies of five of these survey reports and found a sixth report online. We also
found summaries of eight additional reports online. Here we report on the methodology used each
year to calculate the privacy indexes and draw some conclusions about which indexes can be used
to infer privacy trends.

This research was supported in part by the Institute for Software Research International, Carnegie
Mellon University and by the Carnegie Mellon CyLab.