SIF Association

This blog is run by the staff of the SIF (Schools/Systems Interoperability Framework) Association for the use of it's members and the general educational community.

It is specifically designed for those who are interested in understanding what SIF is about, where the standard is going and how Schools, Districts and State Educational Authorities will benefit.



Wednesday, November 28, 2012

Lions, Tigers and Data Models... Oh My!

CEDS on the Wire and SIF Data Models


With the NCES’s Common Education Data Standard (CEDS) v3 release upcoming after the first of the year, it is important now for the SIF community to elaborate on the "CEDS on the Wire" motto for the SIF US 3.0 Data Model.  Last January the US Management Board leadership, lead by LEA, SEA and marketplace providers, set the strategic direction for the community to use our model driven approach to include CEDS as the core for the maturing SIF Data Model in the United States.
SIF Implementation Strategy for CEDS

The CEDS Model is an integral part of the SIF Implementation Specification Data Models.  More specifically, CEDS is a key component in the SIF Logical Data Model.  This logical model forms the basis for all implementable SIF data models.
Beginning with its 3.0 Specification, SIF uses a series of intermediary data models in order to produce implementable data models.  These data models use a “stack” approach to building an implementable model. And while CEDS is not the only important building block in the SIF Data Model Stack, it is 100% represented in the SIF Implementation Specification Data Model.
The stack represents data models along the conceptual -> logical -> physical data model continuum.  In this paradigm, the SIF Entity Model and the SIF Payload Model together make up the SIF Implementation Specification. 
 


Some important points about the SIF Data Model Stack:
  • The SIF approach to data models includes the continuum from conceptual/information models to physical models.
  • Conceptual/Logical models (a.k.a., information models) are bound (or serialized) to a particular technology such as XML for implementation. We are representing the logical model in UML as an intermediate step toward XML that is free from the technical and implementation concerns of XML.
  • Physical models are implementation models because they take use cases, serialization method (e.g. XML) and locale-specific usage into account.
  • Only physical data models are implementable, where conceptual and logical data models are not.

How are the SIF Data Models Created?

The Model Driven Approach builds successive data models on the solid foundations of conceptual and logical models.  These foundational models are necessary and convenient because they allow us to talk about education data without the interference of database technology or implementation concerns.  These concerns are addressed later during physical data model discussions.
SIF has a strong tradition of a use-case-driven approach to development.  This approach is also incorporated into the SIF development process to insure that real-world needs are addressed in the final data model. This is accomplished using the model driven architecture (MDA) approach illustrated below.



CEDS on the Wire

The SIF 3.0 Data Model Implementation Specification will provide a flexible and complete data model with which to implement CEDS.  In addition, the SIF 3.0 Infrastructure Specification will provide many options and components for the transport of CEDS data elements.

The SIF Association remains a strong supporter and participant in CEDS.  The Association participates in the development of CEDS and is committed to providing a comprehensive data model that incorporates all of the CEDS data elements. Stay tuned for the release of the SIF Version 3.0 Data Model Implementation Specification soon after the release of CEDS v3.