Overview

The Credential Transparency Description Language (CTDL) is a family of de facto open standards developed by Credential Engine. Its primary purpose is to provide a common, unified language for describing credentials and related resources (like learning opportunities, competencies, assessments, pathways, and organizations) as linked open data. CTDL originally released on November 17, 2016, and new releases come out regularly, at least twice a year.

CTDL is a comprehensive dictionary and set of rules that allows different systems and organizations to "speak the same language" when exchanging information about credentials, such as describing and relating adjacent resources like assessments, learning resources, work roles, occupations, pathways, and other resource types. This enables:

• Search and Discovery: Making it easier for learners, employers, and other stakeholders to find, understand, and compare credentials from various sources.
• Cross-System Interoperability: Facilitating the seamless exchange of credential data between different platforms, institutions, and countries.
• Informed Decision-Making: Providing clear, consistent, and machine-readable information about credential costs, time to earn, requirements, transfer value, and job applicability.
• AI and Machine Learning: Offering structured data that is highly valuable for training and refining AI models used in skills mapping, career exploration, and learning recommendations.

CTDL is built on the principles of the Resource Description Framework (RDF) and the semantic web, which means it's designed to link data together and provide semantic meaning to terms. Credential Engine's tools, such as the Credential Registry and Credential Finder, rely heavily on CTDL to publish and display credential information as linked open data.

Using this language, learners and workers can understand the availability, costs, time, and value of different credentials. This can give them greater agency and access to navigate the full range of learning and career opportunities. Credential providers and educators are able to more clearly describe the credentials they offer, explain their quality and value, and highlight how they help meet the needs of individuals, businesses, and the community. Employers can discover and hire people who have the skills and competencies they need by effectively signaling job requirements. And policymakers and thought leaders can better understand credentials, allowing them to forge equitable solutions to support a strong economy.

Partners

CTDL grew out of a broader initiative called the Credential Transparency Initiative (CTI), which went from 2013 - 2017 and resulted in the nonprofit Credential Engine, with the following original partners:

• The George Washington University's Institute of Public Policy (GWIPP)
• Workcred (an affiliate of the American National Standards Institute)
• Southern Illinois University (SIU) Carbondale's Center for Workforce Development

Funders

Original funding for CTI came from the Lumina Foundation, and ongoing funding that support the CTDL development continues to come from a variety of foundations and businesses.

Resources

Credential Transparency | Credential Registry 

CTDL Fact Sheet

Credential Engine Schemas Handbook

The Value of CTDL for AI

7 Things you should know about CTDL | EDUCAUSE (2018, December)