CUSUM: a credible method for the determination of authorship?

Authorship attributions based upon the CUSUM (Cumulative Sum Analysis) method are still being presented in court proceedings as evidence despite the findings of several independent researchers that the method is unreliable. This paper describes the shortcomings of the method, presents further examples of its failures and summarises the findings of other researchers. The CUSUM method is seen to be discredited and should not be accepted as providing reliable evidence of authorship of either the written or the spoken word.