A statistical test to show negligible trend

dc.contributor.author Dixon, Philip
dc.contributor.author Pechmann, Joseph
dc.contributor.author Dixon, Philip
dc.contributor.department Statistics
dc.date 2018-02-17T11:34:00.000
dc.date.accessioned 2020-07-02T06:57:52Z
dc.date.available 2020-07-02T06:57:52Z
dc.date.copyright Sat Jan 01 00:00:00 UTC 2005
dc.date.issued 2005-01-01
dc.description.abstract <p>The usual statistical tests of trend are inappropriate for demonstrating the absence of trend. This is because failure to reject the null hypothesis of no trend does not prove that null hypothesis. The appropriate statistical method is based on an equivalence test. The null hypothesis is that the trend is not zero, i.e., outside an a priori specified equivalence region defining trends that are considered to be negligible. This null hypothesis can be tested with two one-sided tests. A proposed equivalence region for trends in population size is a log-linear regression slope of (−0.0346, 0.0346). This corresponds to a half-life or doubling time of 20 years for population size. A less conservative region is (−0.0693, 0.0693), which corresponds to a halving or doubling time of 10 years. The approach is illustrated with data on four amphibian populations; one provides significant evidence of no trend.</p>
dc.description.comments <p>This is an article from <em>Ecology</em> 86 (2005): 1751, doi:<a href="http://dx.doi.org/10.1890/04-1343" target="_blank">10.1890/04-1343</a>. Posted with permission.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/stat_las_pubs/44/
dc.identifier.articleid 1058
dc.identifier.contextkey 8057543
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath stat_las_pubs/44
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/90642
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/stat_las_pubs/44/2005_Dixon_StatisticalTest.pdf|||Sat Jan 15 00:17:34 UTC 2022
dc.source.uri 10.1890/04-1343
dc.subject.disciplines Statistics and Probability
dc.subject.keywords Ambystoma
dc.subject.keywords amphibian decline
dc.subject.keywords Desmognathus
dc.subject.keywords equivalence tests
dc.subject.keywords population trends
dc.subject.keywords statistical power
dc.subject.keywords testing for no effect
dc.title A statistical test to show negligible trend
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication 7b3eb8d2-a569-4aba-87a1-5d9c2d99fade
relation.isOrgUnitOfPublication 264904d9-9e66-4169-8e11-034e537ddbca
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