What are indicators?
Indicators help cities, communities, and other groups measure progress toward their goals. Indicators can be used to compare the status of different places or track change over time for an issue of importance. This information helps people understand the results of policies, identify where progress has been made, and highlight changes or disparities that are inconsistent with community goals.
What are the different types of indicators and what information do they provide?
Different types of indicators are appropriate for different applications. The World Health Organization divides indicators into four types: descriptive, performance, efficiency, and total welfare (aggregate). These types are not necessarily exclusive. For instance a community may select a performance indicator that is also a descriptive or efficiency indicator. Nonetheless these categories help to clarify different ways in which indicators are used to measure outcomes.
- Descriptive indicators measure the current state of a community with regard to one specific issue of interest, such as acres of parkland or vehicle miles traveled in the past year. These indicators can be used to provide a snapshot assessment of current conditions, compare conditions in different neighborhoods or places, or measure trends over time.
- Performance indicators (also known as performance measures) are designed to assess the outcomes of a particular policy or program, such as the percentage of all new development occurring within a designated urban growth area, . Performance indicators are often linked to a baseline reference value in order to assess whether progress is being made over time as well as the rate of progress. Performance indicators are also often linked to a specific policy target. For instance, a community may declare that by the year 2016 98% of all new commercial and residential development will be located within designated urban growth areas. Then the community can measure progress towards this goal to help assess whether current laws, policies, and programs are sufficiently effective in channeling new growth.
- Efficiency indicators show the efficiency of production and consumption processes, such as vehicle miles traveled per capita or energy use per household. Efficiency indicators are often the most useful to track over time as they facilitate accurate comparisons by accounting for background changes such as population growth.
- Aggregate indicators combine separate measures about several different community dimensions into one indicator (or index) that illustrates overall progress. They distill large amounts of information down to one value that summarizes a system as a whole Examples include, a community sustainability score or the Dow Jones Index. Aggregate indicators efficiently communicate a lot of information but, due to the information lost in aggregation, are often too simplified to inform action.
 Adapted from Bauer, R. 1967. Social indicators. Cambridge, MA: M.I.T. Press.