Monitoring Sample Designer (GRTS design support)

Project Description

A master sample is essentially a list of sites needed for a complete census of an area of interest and a list of attributes assigned to each site. A master sample can be created using the Generalized Random-Tessellation Stratified (GRTS) technique, which creates the list of sites but also retains randomization and spatial balance if the full list of sites is subset for sampling. Because conducting a complete census is often cost prohibitive, a master sample for an area of interest can be used to select a randomized, spatially balanced set of representative sampling locations (for more comprehensive materials about master sample details, please see the references listed at the end of this summary). The master sample concept, along with other monitoring and monitoring design tools, has broad applicability to address status and trends questions in the estuarine and near shore marine areas (area-based master sample), in addition to the status and trends of attributes along linear stream networks.

As part of the Integrated Status and Trends Monitoring (ISTM) effort, PNAMP (through Oregon State University) developed a prototype web-based master sample tracking and management system to support the ISTM demonstration for the lower Columbia ESU. The next step was to fully develop this tool into a regional resource that could support the interests of increasing numbers of users in drawing samples from the population domain. The system is intended to allow users to know who else has selected sites from the master sample covering stream networks in their domains; to design individual or integrated monitoring programs; to know how existing sites relate to a common master sample; and what data are collected at the site over time.

In the fall of 2011, PNAMP convened a working group to evaluate the prototype and develop requirements for a regional tool. Over the next year, PNAMP worked with Sitka Technology Group to develop a regionally accessible tool based on information gleaned during the prototype development, as well as user feedback. The resulting application, the Monitoring Sample Designer, facilitates the process of: building a sample design using a probabilistic site selection (using the GRTS algorithm) to generate a spatially‐balanced set of sites for status and trends monitoring; defining the target frame; stratification; site evaluation; and creating panels. It also supports creation of permanent, sharable online documentation of users’ work.

Since 2011, PNAMP has worked with subject matter experts to expand the Sample Designer. We have added additional workflow to support documenting opportunistic sample design. We are currently working with partners to improve usability of the tool.

For more details about the master sample concept, please see:
Larsen, D.P., A.R. Olsen, and D.L. Stevens. 2008. Using a master sample to integrate stream monitoring programs. JABES 13: 243-254.

Stevens, Jr., D.L. and A. R. Olsen. 2004. Spatially-balanced sampling of natural resources. J. American Statistical Association 99: 262-278.

Stevens, Jr., D.L., D. P. Larsen, and A. R. Olsen. 2007. The role of sample surveys: why should practitioners consider using a statistical sampling design? pp 11-24 in D. H. Johnson, B. M. Shrier, J. S. O’Neal, J. A. Knutzen, X. Augerot, T. A. O’Neill, and T. N. Pearsons. Salmonid field protocols handbook: techniques for assessing status and trends in salmon and trout populations. American Fisheries Society, Bethesda, MD.

Project Team

The Project Team consists of funded and in-kind participants that provide subject matter expertise and/or use cases for the requirements analysis. Funding from Bonneville Power Administration supports requirements development and initial development of the tool. Phil Larsen and Don Stevens are assisting with subject matter and statistical expertise. Sitka Technology Group is providing support for requirements analysis and further development. Becca Scully is serving as the project manager.


Updates to the Sample Designer tool

July 13, 2017 - 3:22pm

PNAMP has been working with to make improvements to the Sample Designer tool. We have loaded two additional master samples, we have built functionality to integrate legacy sites into a GRTS sample draw and we have made improvements to the work flow. We will continue to seek feedback from regional and national partners. Stay tuned for updates!

Designs loaded

April 1, 2014 - 3:32pm

Several designs have been loaded into the Sample Designer to date, including many designs using the CHaMP protocol and the Watershed Health and Salmon Recovery protocol from the Washington Department of Ecology. Several more designs are still on the waiting list to be uploaded. There are currently 43 sample designs in the tool, 16 of which are finalized. We recommend increased support in the coming year to load additional designs. Since initial development, we have also expanded the Sample Designer tool to support creation and documentation of non-GRTS (non-probabilistic) designs. Currently, this support is limited to ‘opportunistic’ and ‘census’ survey types, but could be expanded if needed.

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