The SDI Group has drafted selection criteria for choosing data sets that most accurately represent each Sustainable Development Indicator. Data is information organized for analysis or used as the basis for decision-making. A data set is a logical collection of similar or related data sharing a common characteristic, such as source, geophysical parameter(s), computation technique, etc. Metadata is descriptive information about data, such as collection date, source, parameter definitions, etc. The chosen data sets must meet the "essential" criteria. They need not meet all of the "desirable" criteria.
1) Known Quality (Essential): The metadata should define the quality of the data in the data set. This includes such information as sensitivity, uncertainty, variability, precision, accuracy, and error.
2) Constant Definition Over Time (Desirable): The data set definition, measurement techniques, and analytical methodologies should not change over time. The data set should contain minimal discontinuities due to changes in analytical and measurement techniques.
3) Sufficient Historical Data Available (Desirable): To identify useful trends for sustainable development, the data should have a long history, preferably covering a 20 to 50 year time period.
4) Available in Electronic Form (Desirable): Data should appear in electronic form ready for manipulation for the final report.
5) Information for National, State, and Local Levels (Desirable): The data should cover the United States and easily break down into the state, regional and local levels.