Learning Tools Interoperability® (LTI®) is a data standard created by the IMS Global Learning Consortium®. This standard is designed to integrate external applications and content into different learning applications using a single framework. LTI has undergone several revisions (and retractions) throughout the past decade. It is important for publishers and platform developers to understand how LTI and interoperability are evolving.
LTI 1.0 launched in 2010 with the goal of creating a standard for integrating external learning tools into a learning management system (LMS). With the variety of LMSs used by schools and universities, LTI aimed to give learning tool publishers a way to easily integrate with whichever LMS the school chose to use. The LMSs themselves supported the concept integration across different platforms, as being able to easily integrate with a growing ecosystem of external learning tools could increase the value of their LMSs to the institutions which used them. Teachers could now adopt curriculum content that integrated with their LMS, regardless of the platform they used.
The first iteration of LTI gave LMS users a way to launch into an external tool via their LMS. A teacher could post a link containing specific parameters to a course in their LMS. A student was then able to click on this launch link, which sent the external tool provider the parameters and digitally signed the payload using OAuth 1.0. Once the LMS posted the message to the tool provider, the provider would respond by displaying the tool in the users web browser.
LTI 1.0 focuses on launching users into external tools. A prime example of a tool that works well with this framework are online textbooks. LTI easily authenticates the students and the parameters passed to the tool provider, letting the provider know what chapters or resources the should student should be looking at. However, as learning tools become more complex, so does the need for more advanced integrations.
In LTI 1.0, the connection between the consumer (student or teacher) and the tool is severed after the initial connection is made. This made actions that require communication between the tool and the LMS, such as grade passback, impossible. LTI 1.1 sought to remedy this by providing a means to pass additional information between an LMS and a tool.
LTI 1.1, introduced in 2012, uses the same launching procedure as LTI 1.0. The difference is that extra parameters will be passed when the user launches into the LMS which gives the tool a location to which an outcome (or grade) can be placed and a ticket which ensures that the outcome is properly labeled for the specific user and course. This entire process is asynchronous. The simplicity of the LTI 1.1 framework led to widespread adoption of the standard.
LTI v1.2 & v2.0
As the complexity of external learning tools grew, so did the need for enhanced services and deeper integrations with learning platforms. LTI 1.2 and 2.0 were developed and released in tandem in 2014 to improve interoperability. LTI 1.2 was seen as a stepping stone of the LTI 1.x framework that publishers could adopt before they had the ability to fully upgrade to LTI 2.0.
LTI 2.0 introduces REST web services as a way of implementing bi-directional services. The method of launching LTI tools remains the same but now allows for discoverable services, architected services, and partner-provided services. However, the LTI 2.0 framework was built around OAuth 1.0, which has since been deprecated. Furthermore, anyone wishing to receive certification for LTI 2.0 had to certify for all services that LTI 2.0 supported, which the publisher of the tool may not have even need to use. Due to increasing concerns about student privacy and the complexity of implementing the framework, LTI 2.0 saw very low levels of adoption across the industry.
LTI 1.3 & LTI Advantage
Due to a lack of widespread adoption and increasing security concerns, IMS Global decided to deprecate the LTI 2.0 (and 1.2) framework. Instead, a new model would be built on the popular LTI 1.1 specification, which would take advantage of industry advancements in security and decrease complexity for tool developers. This new core version is called LTI 1.3 with services packaged as LTI Advantage.
LTI 1.3 is a framework that adopts modern security OAuth 2.0 and JSON Web Tokens (JWT). LTI 1.3 also adopts the OpenID Connect (OIDC) specifications. Services, such as the Outcomes and Membership services in LTI 1.1, are now decoupled from the core LTI framework. This allows updates to be made to the core LTI 1.3 specification without needing to update the entire suite of LTI services, thus making the process of updating and re-certifying LTI 1.3 compliant tools much simpler.
LTI Advantage is a set of services that are to be used on top of the LTI 1.3 security model. These services are called Names and Roles Provisioning (formerly Memberships in LTI 1.1), Assignment and Grade Services (formerly Outcomes), and Deep Linking. LTI Advantage is designed to allow adopters of the LTI 1.3 specification to implement all or only some of the services, depending on their needs. Note that LTI 1.3 certification is a prerequisite for LTI Advantage certification.
As of May 2019, the IMS Global Consortium, the organization responsible for updating and maintaining the LTI specifications, has officially deprecated all versions of LTI prior to the release of 1.3 and Advantage. The current recommended upgrade path for publishers is to build on the LTI 1.1 model and develop applications using the core LTI 1.3 framework, intended to enhance user and data privacy. LTI Advantage is now the specification whereby current services are updated and new services will be added. For more information on LTI Advantage and its services, please see our article on this topic.
Learning Tools Interoperability® (LTI®) is a trademark of the IMS Global Learning Consortium, Inc. (www.imsglobal.org)