In the past, I have been asked by publishers to review three different
proposals for introductory statistics textbooks which contained this
idea. "We should not do t tests for samples with fewer than six
observations but should always use rank methods." This is the reverse
of my own view, as the Wilcoxon, Sign, Spearman, Kendall, and
Mann-Whitney methods cannot produce two-tailed P values less than 0.05
for any data, all orderings arising in more than 5% of possible
samples. I did not discover where this misleading idea came from,
because none of these authors gave a reference and as it was
confidential I could not ask them. Does anybody know of a published
work which contains this idea?
Martin
--
***************************************************
J. Martin Bland
Prof. of Health Statistics
Dept. of Health Sciences
Seebohm Rowntree Building Area 2
University of York
Heslington
York YO10 5DD
Email: [log in to unmask]
Phone: 01904 321334 Fax: 01904 321382
Web site: http://martinbland.co.uk/
***************************************************
|