ÖйúAƬ

As a Fellow of the Royal Statistical Society, I was very disappointed to see Martin Griffiths, national coordinator for science journalism training at the Royal Statistical Society (RSS), excuse the use of the word "tricks" in an email by researchers at the University of East Anglia's Climatic Research Unit (CRU) ("There's more to a story than facts and figures", 25 November).

The word "tricks" has no technical meaning in statistics. In response to concern about reported unemployment figures in the 1980s, the RSS agreed that changing the data presented on a graph without explicitly marking it and stating in a footnote the nature of the change (ie, the method of data collection, definition, measuring instrument and so on) is very poor statistical practice. That is, it is wrong.

Scientific figures should be designed to inform, not to use "Mike's Nature trick" to "hide the decline" (as Phil Jones, former chief of the CRU, put it). Anyone who wishes to claim a specialist meaning should be able to reference that meaning in a standard textbook.

J.L. Hutton, Department of statistics, University of Warwick.