Skip to Main Content
Testing hypotheses for differences between linear regression linesAuthor(s): Stanley J. Zarnoch
Source: Res. Note SRS-17. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 20 p.
Publication Series: Research Note (RN)
Station: Southern Research Station
Download Publication (4.06 MB)
DescriptionFive hypotheses are identified for testing differences between simple linear regression lines. The distinctions between these hypotheses are based on a priori assumptions and illustrated with full and reduced models. The contrast approach is presented as an easy and complete method for testing for overall differences between the regressions and for making pairwise comparisons. Use of the Bonferroni adjustment to ensure a desired experimentwise type I error rate is emphasized. SAS software is used to illustrate application of these concepts to an artificial simulated dataset. The SAS code is provided for each of the five hypotheses and for the contrasts for the general test and all possible specific tests.
- You may send email to email@example.com to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationZarnoch, Stanley J. 2009. Testing hypotheses for differences between linear regression lines. Res. Note SRS-17. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station. 20 p.
KeywordsContrasts, dummy variables, F-test, intercept, SAS, slope, test of conditional error
- Twig and foliar biomass estimation equations for major plant species in the Tanana River Basin of interior Alaska.
- White Oak Growth after 23 Years in a Three-Site Provenance/Progeny Trial on a Latitudinal Gradient in Indiana
- The effects of surface-applied jasmonic and salicylic acids on caterpillar growth and damage to tomato plants
XML: View XML