Environmental and Ecological Statistics

, Volume 8, Issue 2, pp 91–107

Cost analysis of composite sampling for classification

  • Glen D. Johnson
  • Ganapati P. Patil

DOI: 10.1023/A:1011374330176

Cite this article as:
Johnson, G.D. & Patil, G.P. Environmental and Ecological Statistics (2001) 8: 91. doi:10.1023/A:1011374330176


When an environmental sampling objective is to classify all the sample units as contaminated or not, composite sampling with selective retesting can substantially reduce costs by reducing the number of units that require direct analysis. The tradeoff, however, is increased complexity that has its own hidden costs. For this reason, we propose a model for assessing the relative cost, expressed as the ratio of total expected cost with compositing to total expected cost without compositing (initial exhaustive testing). Expressions are derived for the following retesting protocols: (i) exhaustive, (ii) sequential and (iii) binary split. The effects of both false positive and false negative rates are also derived and incorporated. The derived expressions of relative cost are illustrated for a range of values for various cost components that reflect typical costs incurred with hazardous waste site monitoring. Results allow those who are designing sampling plans to evaluate if any of these compositing/retesting protocols will be cost effective for particular applications.

cost-effectiveness environmental sampling human health sampling observational economy 

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Glen D. Johnson
    • 1
  • Ganapati P. Patil
    • 1
  1. 1.Center for Statistical Ecology and Environmental Statistics, Department of StatisticsPennsylvania State UniversityUniversity Park

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