This report is a reissue of a paper entitled, "Electronic computer seasonal adjustments--tests and revisions of U.S. census methods" [by Julius Shiskin]. The paper was presented at a conference on the use of electronic computers for seasonal adjustments held in Paris, November 28-30, 1960, under the auspices of the Organization for European Economic Cooperation.

The most widely used statistical method in seasonal adjustment is implemented in the X-11 Variant of the Census Method II Seasonal Adjustment Program. Developed by the US Bureau of the Census, it resulted in the X-11-ARIMA software and the X-12-ARIMA. While these integrate parametric methods, they remain close to the initial X-11 method, and it is this "core" that Seasonal Adjustment with the X-11 Method focuses on. It will be an important reference for government agencies, and other serious users of economic data.