This Article  • References  • Full text PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Contact me when this article is cited  Related Content  • Similar articles in this journal  Social Bookmarking   What's this?

Incorrect Use of 2

RICHARD H. BROWNE, PHD
Department of Medical Computer Science Southwestern Medical School The University of Texas Health Science Center at Dallas 5323 Harry Hines Blvd Dallas, TX 75235

Am J Dis Child. 1978;132(8):819.

	Since this article does not have an abstract, we have provided the first 150 words of the full text PDF and any section headings.

To the Editor.—An article by Weston et al (Am J Dis Child 131:1241-1242, 1977) exemplifies a continuing misuse of ² methodology in the literature. This is the use of ² to compare things other than the number of "successes" in N trials.^1(p43)

For the ² method to be proper, the mean percent of cells responding would have to include the total number of cells used in each group. What the authors wanted to do was compare two groups of data that just happened to be percent cells responding for each subject.

The most appropriate method of analysis would have been the Mann-Whitney U test.^1(p109) The usual t test could have been used but it would have required an arc sine transformation of each value,^1(p185) a tedious problem.

Weston et al found no substantial difference between newborns and controls for monocyte phagocytosis and bactericidal activity. Using the summary statistics provided, I . . . [Full Text PDF of this Article]

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter     What's this?