Variance components estimation for continuous and discrete data, with emphasis on cross-classified sampling designs

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Edited by: Robert A. GitzenJoshua J. MillspaughAndrew B. Cooper, and Daniel S. Licht

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Abstract

Variance components may play multiple roles (cf. Cox and Solomon 2003). First, magnitudes and relative magnitudes of the variances of random factors may have important scientific and management value in their own right. For example, variation in levels of invasive vegetation among and within lakes may suggest causal agents that operate at both spatial scales – a finding that may be important for scientific and management reasons. Second, variance components may also be of interest when they affect precision of means and covariate coefficients. For example, variation in the effect of water depth on the probability of aquatic plant presence in a study of multiple lakes may vary by lake. This variation will affect the precision of the average depth-presence association. Third, variance component estimates may be used when designing studies, including monitoring programs. For example, to estimate the numbers of years and of samples per year required to meet long-term monitoring goals, investigators need estimates of within and among-year variances. Other chapters in this volume (Chapters 7, 8, and 10) as well as extensive external literature outline a framework for applying estimates of variance components to the design of monitoring efforts. For example, a series of papers with an ecological monitoring theme examined the relative importance of multiple sources of variation, including variation in means among sites, years, and site-years, for the purposes of temporal trend detection and estimation (Larsen et al. 2004, and references therein).

Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Variance components estimation for continuous and discrete data, with emphasis on cross-classified sampling designs
DOI 10.1017/CBO9781139022422.013
Year Published 2012
Language English
Publisher Cambridge University Press
Publisher location Cambridge; New York
Contributing office(s) Upper Midwest Environmental Sciences Center
Description 28 p.
Larger Work Type Book
Larger Work Title Design and analysis of long-term ecological monitoring studies
First page 200
Last page 227
Online Only (Y/N) N
Additional Online Files (Y/N) N