Indicators
What is an ROE indicator?
A ROE indicator is a numerical value derived from actual measurements of a pressure, state or ambient condition, exposure or human health or ecological condition over a specified geographic domain, whose trends over time represent or draw attention to underlying trends in the condition of the environment.
The numerical values for the indicators presented in the ROE were gathered from many different federal and state agencies and non-government organizations using a variety of methods. Over time, as improvements are made in measurement technology, sample design, quality assurance, and topic coverage, a more complete picture of the environment will become available. EPA is committed to releasing periodic updates of the ROE so that information on environmental condition and trends can be provided on a long-term basis to environmental professionals and interested members of the public.
How are the indicators chosen?EPA uses the following criteria to determine what indicators should be included in the report:
- The indicator is useful. It answers (or makes an important contribution to answering) a question in the ROE.
- The indicator is objective. It is developed and presented in an accurate, clear, complete, and unbiased manner.
- The underlying data are characterized by sound collection methodologies, data management systems to protect its integrity, and quality assurance procedures.
- Data are available to describe changes or trends and the latest available data are timely.
- The data are comparable across time and space, and representative of the target population. Trends depicted in this indicator accurately represent the underlying trends in the target population.
- The indicator is transparent and reproducible. The specific data used and the specific assumptions, analytic methods, and statistical procedures employed are clearly stated.