Adjwgt_FrameNR: Adjust design weights for frame error.

In tmcd82070/SDrawNPS: Sample Draw NPS

Description

Takes data for a single survey year and calculates site-specific design weights after accounting for frame error and nonresponse, while assuming missing-completely-at-random missingness.

Usage

Adjwgt_FrameNR(dat, popn, evalstatus = "EvalStatus", wgt = "wgt")

Arguments

dat	A GRTS-design csv file generated from a GRTS sample draw, with individual sites forming its rows.
popn	A text string identifying the type of membership of a site. Use popn="Target" if the site is not needed, or popn="Sampled" for scope of inference.
evalstatus	A text string identifying the variable within dat describing the evaluation status of sites in dat. See ‘evalstatus Variable Specifications.’
wgt	A text string identifying the variable within dat containing site-specific design weights.

Details

This routine is called by the sampling analysis Graphical User Interface (GUI), i.e., function analysis.GUI, when its ‘Optional Weight Inputs’ ‘Adjust Weights?’ radio button is set to ‘Yes.’ See analysis.GUI. Generally, this function is not intended to be called directly by the user.

When the analysis.GUI routine requests adjustment of weights, function Adjwgt_FrameNR modifies the included weights wgt in dat for frame error and nonresponse. The methodology assumes any missing sites are missing completely at random. Weighting adjustment is appropriate for a single survey period (e.g. season or year) and does not accommodate weighting for summary statistics of more than one survey period.

Value

A numeric vector adj.wt of length equal to the number-of-site rows originally contained in dat.

evalstatus Variable Specifications

Each row of dat represents a randomly selected site from the GRTS sample draw. Generally, dat contains additional variables for data collected during the survey. Essentially however, dat must contain a field evalstatus that describes the sampling nature of all sampled sites. An error is returned if the evalstatus variable is not formatted to be one of the following four values:

1. "Target - Sampled" – The site is a member of the target population and data were successfully collected.

2. "Target - Not Sampled" – The site is a member of the target population, but data were not collected, e.g., due to innaccessibility, landowner denial, etc.

3. "Not Evaluated" – The site was not assessed by observer crews.

4. "Non-Target" – The site is not a member of the target population.

Author(s)

Leigh Ann Starcevich ([e-mail])

References

Little, J. A. R., and Rubin, D. B. (2002). Statistical analysis with missing data, 2nd edition. John Wiley and Sons, Inc., New Jersey

Lessler, J. T. and Kalsbeek, W. D. (1992). Nonsampling errors in surveys. John Wiley and Sons, New York.

Oh, H. L. and Scheuren, F. J. (1983). Weighting adjustment for unit nonresponse. Pages 143-184 in W. G. Madow, I. Olkin, and D. B. Rubin, editors. Incomplete data and in sample surveys. (Vol. 2). Academic Press, New York.

Starcevich L. A., DiDonato G., McDonald T., Mitchell, J. (2016). A GRTS User's Manual for the SDrawNPS Package: A graphical user interface for Generalized Random Tessellation Stratified (GRTS) sampling and estimation. National Park Service, U.S. Department of the Interior. Natural Resource Report NPS/XXXX/NRR—20XX/XXX.

See Also

analysis.GUI

Examples

# Adjust design weights for frame error
Adjwgt_FrameNR(dat=sampData,popn="Target - Surveyed",evalstatus="EvalStatus",wgt="wgt"))
  

tmcd82070/SDrawNPS documentation built on May 31, 2019, 4:37 p.m.