Stat-403/Stat-650 : Intermediate Sampling and Experimental Design ...

Statistical Signigicance TestingThe Insignificance of StatisticalSignificance TestingBy Douglas H. Johnson 1Abstract: Despite their wide use in scientific journals such as The Journal of Wildlife Management, statisticalhypothesis tests add very little value to the products of research. Indeed, they frequently confuse theinterpretation of data. This paper describes how statistical hypothesis tests are often viewed, and then contraststhat interpretation with the correct one. I discuss the arbitrariness of P-values, conclusions that the nullhypothesis is true, power analysis, and distinctions between statistical and biological significance. Statisticalhypothesis testing, in which the null hypothesis about the properties of a population is almost always known apriori to be false, is contrasted with scientific hypothesis testing, which examines a credible null hypothesisabout phenomena in nature. More meaningful alternatives are briefly outlined, including estimation andconfidence intervals for determining the importance of factors, decision theory for guiding actions in the faceof uncertainty, and Bayesian approaches to hypothesis testing and other statistical practices.Key words: Bayesian approaches, confidence interval, null hypothesis, P-value, power analysis, scientifichypothesis test, statistical hypothesis test.This resource is based on the following source (Northern Prairie Publication 1057):Johnson, Douglas H. 1999. The Insignificance of Statistical SignificanceTesting. Journal of Wildlife Management 63(3):763-772.This resource should be cited as:Johnson, Douglas H. 1999. The Insignificance of Statistical SignificanceTesting. Journal of Wildlife Management 63(3):763-772. Jamestown,ND: Northern Prairie Wildlife Research Center Home Page.http://www.npwrc.usgs.gov/resource/1999/statsig/statsig.htm(Version 16SEP99).Editor's Note: Doug Johnson received The Wildlife Society Award for Outstanding Publication in Wildlife61http://www.npwrc.usgs.gov/resource/1999/statsig/statsig.htm (1 of 3) [12/6/2002 3:10:51 PM]