You are here: Home
/ Publication Information
Title: Standard error of estimated average timber volume per acre under point sampling when trees are measured for volume on a subsample of all points.
Author: Johnson, Floyd A.;
Source: PNW Old Series Research Notes No. 201, p. 1-6
Publication Series: Research Note (RN)
Description: This report assumes a knowledge of the principles of point sampling as described by Grosenbaugh, Bell and Alexander, and others.
Whenever trees are counted at every point in a sample of points (large sample) and measured for volume at a portion (small sample) of these points, the sampling design could be called ratio double sampling. If the large sample is either a completely random or a systematic sample of the area being cruised, and if the small sample is either a completely random or a systematic sample from the large sample, formula 1 (below) is appropriate for calculating an estimate of average volume per acre. Formula 1 is already available in the literature on point sampling, and is shown here merely to introduce the standard error of estimated average volume (formula 2) which is not well known. Formula 2 is strictly appropriate only for completely random samples. If used with systematic samples, it must be considered an approximation.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication. (Please specify exactly
which publication you are requesting and your mailing address.)
XML: View XML
Johnson, Floyd A. 1961. Standard error of estimated average timber volume per acre under point sampling when trees are measured for volume on a subsample of all points. PNW Old Series Research Notes No. 201, p. 1-6
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility