The normal way of keeping a tally on a sheet of paper is with four vertical slashes followed by a diagonal slash through those four. But John Tukey came up with an alternative that is less likely to create errors. This blog post describes this method.

Cook, John D.. Tukey tallying. Available in html format.

This Recommendation was added to the website on 2019-11-08 and was last modified on 2020-02-04. You can find similar pages at Descriptive statistics.