R Code for Developing Multimetric Indices

This is legacy code used to screen biological metrics and develop multimetric indices using a "best subsets" approach. This code has been used to develop several multimetric indices related to NARS surveys. 

Impact/Purpose

The set of code in this sub-product represents processes that have been in use for over a decade. The R scripts and associated documentation are used to screen candidate biological metrics for use in a multimetric index, which is used to measure biological condition. There are also two R scripts that are used to run "best subsets" analysis of metrics to help the user identify the most useful combinations of metrics for a multimetric index. The R code only provides information to the user and does not make any decisions for the user. The code included here is intended provide tools for States, Tribes, and local agencies that are developing indicators for bioassessment. 

Citation

Blocksom, K. R Code for Developing Multimetric Indices. U.S. Environmental Protection Agency, Washington, DC, 2025.

• https://github.com/USEPA/NARS_multimetric_code