Developers - Content

Overview

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:25 -0400

There are many educational applications and systems in the market today. Thanks to the work of organizations like IMS Global, many of these can represent their data using a variety of standards ranging from those for content packaging, questions and tests to those for metadata and identity. These "data representation" standards allow data to be migrated from one system to another. Most educational applications also work with various standardized protocols such as SOAP, Z39.50, SRW, POP and IMAP. These allow systems to communicate with each other and exchange content in real time.

The O.K.I. open service interface definitions (OSIDs) seek to standardize interfaces to basic functionality so that one application (an OSID consumer) can access specific data and functionality from another application (an OSID provider) in real time. For example, a digital asset management system can make its collections of assets accessible to a learning management system (LMS) by exposing an implementation of the Repository OSID. The LMS then need only be able to consume that OSID (i.e. be able to call functions in the digital asset management system as defined by the OSID).

Conceptual Architectural Framework

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:25 -0400

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Scott Thorne. "Conceptual Architectural Framework" O.K.I. Project Site. MIT, 2004

At the present time the large community of educational systems and content providers and their users are having trouble understanding the complicated specifications world. To help in the understanding of this area, we can use a general architectural pattern and functional area breakout to help organize and give a context to this information.

Access to Old O.K.I. Project Site

Jeff Merriman - nobody@example.net — Tue, 24 Jun 2008 07:24:11 -0400

If there is information that you wish to access on the old O.K.I. project web site you may still visit that site by going to http://okicommunity.mit.edu/

We feel that we have populated this site all of the important information and files from the old one, but please add comments below if there is anything you see missing (registration required, follow "visitor registration" at the top of the page)

Specifications

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:26 -0400

DEFINITION:

O·SID [o'cid] n. O.K.I. uses the term Open Service Interface Definition (OSID) to differentiate its service based specifications from the broader class of application programming interfaces. The O.K.I. architecture exposes a carefully selected collection of services. The definition of these services enforces a programming model that maintains a sharply delineated boundary between O.K.I. compliant applications and O.K.I. service implementations.

OKI publishes OSIDs, which are not quite like typical specifications. The OSIDs are a kind of conceptual API, which can be expressed in different programming languages. The bindings to these languages are interfaces (or the nearest thing to that concept that the language has). The interfaces require implementations by service providers, which are separate releases by vendors or other contributors.

In V2 (the current version) of OKI a lowest-common-denominator Java language binding acted as both language-specific binding and specification for the OSIDs. As new languages are being added, an XML expression of the "conceptual API" has been released (XOSIDs, available on Sourceforge), along with XSLT for transformation into language-specific bindings. This is the approach that is being followed for V3 of the OSIDs. Both the XML-based specification and the language-specific bindings will be part of the revision process for V3.

Language Bindings

Alex Chapin - nobody@example.net — Thu, 29 Jul 2010 20:52:57 -0400

There are currently two fully released language bindings for the OSIDs, one for Java and one for PHP. Below are links to download these from SourceForge, as well as links to documentation.

Java
OSID v2 Bindings Download

Documentation

PHP
OSID v2 Bindings Dowload

Documentation

See: OSID V3 section of this site for the latest developments

Types

Alex Chapin - nobody@example.net — Wed, 25 Jun 2008 08:44:09 -0400

What OKI calls "Types" are crucial to the interoperability of the OSIDs. The OSIDs themselves are written very generically. It is only through a common understanding of the out-of-band "Types" that applications can make use of the most important functionality. For example, the seach methods in the Repository OSID require a Search Type. It is only by defining a commonly understood set of Search Types that different repositories can be searched in the same way.

The Types themselves are not part of the OKI specification per se; they are expected to be developed by the community as implementations are created. Implementors of OSIDs are strongly encouraged to submit their Types to the community at large.

See OSID V3 Type Package ? for latest on developments

Architecture

Alex Chapin - nobody@example.net — Thu, 29 Jul 2010 20:52:57 -0400

Although the OSIDs represent an approach to a Service-Oriented Architecture (SOA), it is different from the more protocol-oriented approaches and has some new concepts to offer. A good place to begin is in our Library, with The Conceptual Architectural Framework.

The OSIDs are continually evolving and was designed to do so. For insight into the thinking behind how this work, see The Architectural Process.

OKI V3 and the Future

Alex Chapin - nobody@example.net — Thu, 29 Jul 2010 20:52:58 -0400

See the OSID V3 section of this site for the latest developments.

Repository Description

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:26 -0400

The Repository OSID covers storing and retrieving digital content, referred to as Assets, as well as information about the Assets. Assets, examples of which include: documents, course material, assessment item, images, video, audio, etc, reside in Repositories which have names and descriptions and which support a specific set of Asset Types.

Repositories are themselves organized by the RepositoryManager that keeps track of repositories and supports certain operations such as searching for Assets across repositories. Associated with each Asset Type is a RecordStructure that defines the format of information comprising the Asset or information describing the Asset. An Asset can have content as well as Records, which are data in the format defined by the Asset’s RecordStructure. Assets may contain other Assets.

See V3 OSID Repository Package ? for updates to this OSID.

Repository White Paper

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:26 -0400

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Open Knowledge Initiative. "Open Service Interface Definitions: Repository" Massachusetts Institute of Technology. Open Knowledge Initiative, 2004

Authentication Description

Alex Chapin - nobody@example.net — Fri, 30 Jul 2010 01:46:21 -0400

The Authentication OSID gathers required credentials from an agent, vouches for their authenticity and introduces the agent to the system. The Authentication OSID permits an application to abstract the authentication process without having to manage the details of the underlying authentication service.

See V3 OSID Authentication Package ? for updates to this OSID.

Authentication White Paper

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:27 -0400

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Open Knowledge Initiative. "Authentication OSID" Massachusetts Institute of Technology.

Authorization Description

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:27 -0400

The Authorization OSID allows an application to establish and query a user's privileges to view, create, or modify application data, or use application functionality.

Authorization White Paper

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:27 -0400

Download (235.36 kB)

"Open Service Interface Definitions: Authorization" Open Knowledge Initiative. Massachusetts Institute of Technology,

Hierarchy Description

Alex Chapin - nobody@example.net — Fri, 30 Jul 2010 01:46:22 -0400

The Hierarchy OSID manages parent-child relationships among elements. In addition to simple tree structures, the OSID supports hierarchy that are recursive and have nodes with multiple parents. User authorizations are usually stored as a hierarchy.

See V3 OSID Hierarchy Package ? for updates to this OSID.

Hierarchy White Paper

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:28 -0400

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"Open Service Interface Definition: Hierarchy" Open Knowledge Initiative.

Agent Description

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:28 -0400

OSID use Agents to represent individuals or processes that invoke specific Services. An example of an Agent is a specific Student, John Doe. This Agent might have the DisplayName “Doe, John ?, the Id 123-45-6789, and a Type indicating a Student. Agents can be organized into Groups. A Group also has a DisplayName, Id, and characterizing Type. In addition, Groups have a description. A Group can contain zero or more Agents. A Group can contain zero or more Groups (subgroups). An Agent can only be added as a member of a Group if it is not already in the Group, but the same Agent can be a member of a subgroup. Agents can have sets of Properties associated with them. Each set of Properties has a Type. The Agent OSID provides a variety of methods for managing these Agents and Groups

Agent White Paper

Alex Chapin - nobody@example.net — Sun, 22 Jun 2008 18:31:28 -0400

Download (71.08 kB)

"Open Service Interface Definition: Agent" Open Knowledge Initiative.

Downloads

Alex Chapin - nobody@example.net — Thu, 29 Jul 2010 20:52:59 -0400

Download

Interoperability

Alex Chapin - nobody@example.net — Fri, 30 Jul 2010 01:41:39 -0400

The measure of ease of integration between two systems or software components to achieve a functional goal. A highly interoperable integration is one that can be easily achieved by the individual who requires the result.

See Redefining Interoperability in the Conversations section of this site.

Integration

Alex Chapin - nobody@example.net — Thu, 29 Jul 2010 23:41:06 -0400

The act of making two systems work together to achieve a functional goal, regardless of how difficult or expensive that task might be.

See Redefining Interoperability in the Conversations section of this site.

O.K.I.

Alex Chapin - nobody@example.net — Thu, 29 Jul 2010 22:50:56 -0400

The Open Knowledge Initiative (O.K.I.) develops and promotes specifications that describe how the components of a software environment communicate with each other and with other enterprise systems. O.K.I. specifications enable sustainable interoperability and integration by defining standards for Service Oriented Architecture (SOA). Through this work O.K.I. seeks to open new market opportunities across a wide range of software application domains.

The O.K.I. project was initially launched in 2001 through a generous grant from the Andrew W. Mellon Foundation, and in collaboration with a number of like minded organizations. Today the O.K.I. Phase II project is housed at the Office of Educational Innovation and Technology, a part of MIT's Dean of Undergraduate Education Office.