The LMS Toolkit is joining data from disparate systems into a common data model, the LMS Unifying Data Model (LMS UDM). That model is based on the use cases (see LMS Toolkit) and also considers the natural state of the data as exposed by instructional systems. The LMS UDM provides a blueprint for the capture of learning management system data for K-12 education organizations.
The initial LMS UDM model was also based on the API capabilities of three large and popular learning applications; this list was identified and prioritized by members of the Ed-Fi community.
It is important to note that the model is not attempting to capture all data out of instructional systems: to do so would not be efficient technically, and much of the data would likely never be used. The project is therefore making careful choices to limit data to those elements the Ed-Fi community has identified as most useful.