The U.S. Departments of Justice, Homeland Security and Health and Human Services collaboratively created the National Information Exchange Model (NIEM) as a standard for data exchange. NIEM brings together communities of people who have similar information needs but may speak different “languages”. The NIEM website explains it this way:

“If I say "vessel" and you say "boat", and he says "ship" and she says "conveyance", we may mean the same thing, but we have no way to tell our computer systems to treat the words as having the same meaning. Until we do, we'll all have separate facts about the same world—pieces of the big puzzle—but no common understanding or way to connect them.

This is the idea behind NIEM. It lets your system and my system speak— even if they've never spoken before— by ensuring that information carries the same consistent meaning across various communities.

Rather than starting from scratch, NIEM can save organizations time and money by providing consistent, reusable, and repeatable data terms, definitions, and processes.”

NIEM has three stewards in the federal government: The U.S. Department of Justice (DOJ), the U.S. Department of Homeland Security (DHS), and the U.S. Department of Health and Human Services (HHS). All 50 states and most federal agencies work with NIEM. When an organization buys into NIEM it agrees  to a “data-dictionary of agreed-upon terms, definitions, relationships and formats— independent of how information is stored in individual systems.” This model can help produce  data that is higher quality, machine readable, more interoperable, and real-time.

NIEM is composed of a Core— data elements that are commonly understood across domains— and a number of Domains, made up of mission specific data that is managed through independent stewards. NIEM has continued to expand in scope, moving beyond its initial focus on justice and homeland security. NIEM communities currently exist around Agriculture, Emergency Management, Immigration, International Trade, Intelligence, Surface Transportation, and more.