p Value fetishism and use of the Bonferroni adjustment Export

@article{citeulike:5788558, abstract = {The p value guidesus injudgements of statistical significance, accepting or rejecting the ''null hypothesis'', but can exert excessive influence over judgements of clinical significance. Karl Marx wrote of the ''fetishismof commodities'' in criticising the undue influence of property on capitalism's social processes. In much the same way, evidence-based medicine has created a ''fetishism of p values''.Where used to make an appraisal of the significance of difference between two groups, the p value is termed the ''significance level''. The convention of relying on p,0.05 to indicate clinical significance is now deeply embedded in our critical appraisal of research papers, to such an extent that we can sometimes forget its true meaning. Ap value less than 0.05 indicates that the differences between, say, two treatment groups will result from''chance'' one time in 20, as a Type I error (signified a). This is conventionally interpreted as indicating clinical significance, useful as an aide memoire but sometimes given unwarranted influence when conceptually detached from the clinical situation in which the test has been conducted. p values must be interpreted in light of the clinical scenario.We misuse p values when treating themina purely dichotomous manner, as ''significant'' or ''not significant''. The difference between p=0.051 and p=0.049 may be actuarially meaningless, and can only be understood with reference to the circumstances and power of the test.}, author = {Morgan, John F.}, citeulike-article-id = {5788558}, citeulike-linkout-0 = {http://dx.doi.org/10.1136/ebmh.10.2.34}, citeulike-linkout-1 = {http://ebmh.bmj.com/cgi/content/abstract/10/2/34}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/17459968}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=17459968}, comment = {Summarized in blog post: 'The evil of Bonferroni adjustments.':http://www.citeulike.org/blog/Zephyrus/9267}, day = {1}, doi = {10.1136/ebmh.10.2.34}, journal = {Evid Based Ment Health}, keywords = {bonferroni, methods, multiple-comparisons, p-value, significance-testing, statistics}, month = {May}, number = {2}, pages = {34--35}, posted-at = {2009-09-15 17:34:58}, priority = {2}, title = {p Value fetishism and use of the Bonferroni adjustment}, url = {http://dx.doi.org/10.1136/ebmh.10.2.34}, volume = {10}, year = {2007} }

TY - JOUR ID - citeulike:5788558 L3 - citeulike-article-id:5788558 N2 - The p value guidesus injudgements of statistical significance, accepting or rejecting the ‘‘null hypothesis’’, but can exert excessive influence over judgements of clinical significance. Karl Marx wrote of the ‘‘fetishismof commodities’’ in criticising the undue influence of property on capitalism’s social processes. In much the same way, evidence-based medicine has created a ‘‘fetishism of p values’’.Where used to make an appraisal of the significance of difference between two groups, the p value is termed the ‘‘significance level’’. The convention of relying on p,0.05 to indicate clinical significance is now deeply embedded in our critical appraisal of research papers, to such an extent that we can sometimes forget its true meaning. Ap value less than 0.05 indicates that the differences between, say, two treatment groups will result from‘‘chance’’ one time in 20, as a Type I error (signified a). This is conventionally interpreted as indicating clinical significance, useful as an aide memoire but sometimes given unwarranted influence when conceptually detached from the clinical situation in which the test has been conducted. p values must be interpreted in light of the clinical scenario.We misuse p values when treating themina purely dichotomous manner, as ‘‘significant’’ or ‘‘not significant’’. The difference between p=0.051 and p=0.049 may be actuarially meaningless, and can only be understood with reference to the circumstances and power of the test. IS - 2 JF - Evid Based Ment Health EP - 35 TI - p Value fetishism and use of the Bonferroni adjustment VL - 10 SP - 34 KW - bonferroni KW - methods KW - multiple-comparisons KW - p-value KW - significance-testing KW - statistics N1 - Summarized in blog post: 'The evil of Bonferroni adjustments.':http://www.citeulike.org/blog/Zephyrus/9267 AU - Morgan, John PY - 2007/05/01/ UR - http://dx.doi.org/10.1136/ebmh.10.2.34 ER -