This workshop will teach users how to create a probabilistic survey design and analyze the resulting data using the R package spsurvey. This package was developed specifically for this purpose and implements the Generalized Random Tessellation Stratified (GRTS) algorithm used to create designs for the National Aquatic Resource Surveys (NARS). This package also can be used to analyze data generated using these designs to estimate population-level characteristics with a known level of uncertainty. The workshop will also cover two R Shiny apps that provide a user-friendly interface that runs package functions to create designs and analyze data following the NARS approach. Participants will have the opportunity to run code in R and/or using the Shiny apps on their laptops and ask the developers of the package and R Shiny apps any questions that come up.If planning to run R code, make sure to download the most recent version of spsurvey before attending the workshop. The most recent version of spsurvey can be downloaded by running install.packages(“spsurvey”) in R.
Attendees would need to supply their own laptop with RStudio and R (> v. 4.0) installed, as well as spsurvey (v. 5.1 or later). We would provide a list of other required packages and access to the GitHub repositories where code is for Shiny apps is available for download. Some experience with R is helpful but not necessary.
Presenters
Karen Blockson, U.S. Environmental Protection Agency, ORD-CPHEA-PESD
Michael Dumelle, U.S. Environmental Protection Agency, ORD-CPHEA-PESD
Garrett Stillings, U.S. Environmental Protection Agency, OW-OWOW-WRAPD-MAB