Premium
Short Communications : Use of linear orthogonal contrasts in analysis of environmental data
Author(s) -
Hoke Robert A.,
Giesy John P.,
Adams John R.
Publication year - 1990
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620090616
Subject(s) - analysis of variance , statistics , data set , range (aeronautics) , environmental science , linear model , mathematics , composite material , materials science
Environmental studies often involve the analysis of many samples from a limited geographic region. The goal of these studies frequently is to compare samples from different areas within the region to determine relative levels of contamination or adverse effects. Analysis of variance (ANOVA) followed by multiple comparison tests is an often‐used data analysis technique in these situations. However, ANOVA followed by the use of linear orthogonal contrasts is a more appropriate method of data analysis if obvious groups of samples for comparison can be identified a priori. The utility of the technique is demonstrated in an analysis of the growth (dry weight) of Chironomus tentans larvae during 10‐d sediment toxicity assays of sediments from western Lake Erie and the Maumee River at Toledo, Ohio. The use of linear orthogonal contrasts revealed several pertinent aspects of the data set which were not apparent after ANOVA followed by multiple range tests.