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LEXS Overview

What is LEXS?

Logical Entity eXchange Specification.

LEXS defines a data model, syntax, semantics, and usage guidelines for implementers of information exchanges. LEXS was created, and is being further developed, to minimize the impact of changing requirements and varied demands for information sharing between sources and consumers of data.

LEXS provides an extensible framework for consistent packaging of the information, with specific placement and markings for various elements of the shared information. The LEXS specifications shield both data sources and data recipients from the complexity of multiple interfaces and allows for the multipurpose use of information: for example, a data item created
by a source can be consumed by multiple recipients that should be able to understand as much or as little of the data as necessary.

With the myriad of programs utilizing NIEM, any superset of data would be too large and unwieldy to be of value, while any specification that is limited to the lowest common denominator is unlikely to meet anyone’s needs. Therefore, LEXS defines a “baseline” level of understanding that is common across all programs that follow the specification, and adds a well-defined extension point that can be utilized by communities of interest, or even individual programs, to utilize additional data elements without impacting compatibility. LEXS supports both structured and unstructured data, and includes rich multimedia attachments. Structured data includes a wide variety of roles and associations in order to provide detailed context for use in analysis.

LEXS supports four categories of operations: Publish/Discover, Search/Retrieve, Subscribe/Notify, and Domain Exchange.  All  utilize the same data model, and only differ in the fields necessary to meet the different use cases.