Journal ArticleDOI
Adaptive Cluster Sampling: Designs with Primary and Secondary Units
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In this article, an initial probability sample is selected and, whenever the observed value of the variable of interest satisfies a given condition, units in the neighborhood of that observation are added to the sample.Abstract:
SUMMARY In adaptive cluster sampling designs, an initial probability sample is selected and, whenever the observed value of the variable of interest satisfies a given condition, units in the neighborhood of that observation are added to the sample. In this paper, the initial design is selected in terms of primary units, while subsequent sampling is in terms of secondary units. Such initial designs include systematic sampling, strip sampling, and other forms of classical cluster sampling. But because of the subsequent addition to the sample of secondary units in the neighborhood of any (secondary) unit that satisfies the condition of interest, the final "clusters" of units obtained through the procedure may be quite different in shape from the initial primary units. The methods described in this paper apply to such sampling situations as whale surveys in which the research vessel temporarily leaves the selected transect to close in on sighted whales, surveys of rare bird species in which initial observations are made at systematically selected sites and additional observations are made in the vicinity of any site at which sufficiently high abundance is observed, and aerial walrus surveys in which the aircraft searches to either side of the preselected transect line whenever a congregation of animals is encountered. Because conventional estimators of the population mean and total are biased with such a procedure, estimators that are unbiased under the adaptive designs are presented in this paper. Variance formulae and unbiased estimators of variance are also given. The designs are illustrated using a point pattern representing locations of individuals or objects in a spatially aggregated population; for such a population, the adaptive designs can be substantially more efficient than their conventional counterparts.read more
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Population Parameters: Estimation for Ecological Models
TL;DR: This book brings together a diverse and scattered literature, to provide clear guidance on how to estimate parameters for models of animal populations, and selects the best approach to parameter estimation for a particular problem.
Journal ArticleDOI
Stratified adaptive cluster sampling
TL;DR: In this article, several types of estimators are developed which are unbiased for the population mean or total with stratified adaptive cluster sampling, which is similar to the adaptive clustering approach in this paper.
Journal ArticleDOI
Efficiency of adaptive cluster sampling for estimating density of wintering waterfowl
TL;DR: In this paper, the National Biological Service, Georgia Cooperative Fish and Wildlife Research Unit, School of Forest Resources, University of Georgia, Athens, Georgia 30602, U.S.A., and Waterfowl Management Section, Florida Game and Fresh Water Fish Commission, 8932 Apalachee Parkway, Tallahassee, Florida 32311.
Journal ArticleDOI
Adaptive sampling in research on risk-related behaviors.
TL;DR: For rare and clustered populations adaptive designs can give substantial gains in efficiency over conventional designs, and for hidden populations link-tracing and other adaptive procedures may provide the only practical way to obtain a sample large enough for the study objectives.
References
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Journal ArticleDOI
A generalization of sampling without replacement from a finite universe.
D. G. Horvitz,D. J. Thompson +1 more
TL;DR: In this paper, two sampling schemes are discussed in connection with the problem of determining optimum selection probabilities according to the information available in a supplementary variable, which is a general technique for the treatment of samples drawn without replacement from finite universes when unequal selection probabilities are used.
Book
Statistical analysis of spatial point patterns
TL;DR: This book provides an introduction to statistical methods for analysing data in the form of spatial point distributions, described in intuitive terms and illustrated by many applications to real data drawn from the biological and biomedical sciences.
Journal ArticleDOI
On the Theory of Sampling from Finite Populations
Journal ArticleDOI
A review of estimating animal abundance.
TL;DR: A review of the literature in the estimation of animal abundance and related parameters such as survival rates and suggest further avenues for research.
Journal ArticleDOI
Adaptive Cluster Sampling
TL;DR: In this article, the authors describe sampling designs in which, whenever an observed value of a selected unit satisfies a condition of interest, additional units are added to the sample from the neighborhood of that unit, if any of these additional units satisfies the condition, still more units may be added.