Ranked set sampling for ecological research: accounting for the total costs of sampling

✍ Scribed by Nicolle A. Mode; Loveday L. Conquest; David A. Marker

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 201 KB
• Volume: 10
• Category: Article
• ISSN: 1180-4009
• DOI: 10.1002/(sici)1099-095x(199903/04)10:2<179::aid-env346>3.0.co;2-#

✦ Synopsis

Researchers aim to design environmental studies that optimize precision and allow for generalization of results, while keeping the costs of associated ®eld and laboratory work at a reasonable level. Ranked set sampling is one method to potentially increase precision and reduce costs by using rough but cheap' quantitative or qualitative information to obtain a more representative sample before the real, more expensive sampling is done. In this report, we investigate under what conditions ranked set sampling becomes a cost-eective sampling method for ecological and environmental ®eld studies where the rough but cheap' measurement has a cost. Ratios of measuring to ranking costs necessary for ranked set sampling to be as cost eective as simple random sampling, for a common precision, are presented for known distributions with and without ranking error. Cost ratios are also presented for a real data set consisting of visually estimated and physically measured stream habitat areas. Results provide speci®c guidelines for when ranked set sampling is appropriate, and cost eective, for ecological and environmental ®eld sampling.