You probably have data on course enrollments and completion and pass rates on course tests, but what about data on how learners are applying their new knowledge? The Experience API (xAPI) can help you collect and track more complete data on your learning programs and their results. An application programming interface (API) is a means for transmitting data across software systems. xAPI allows you to document and track learning experiences. In this issue of TD at Work, “Making Sense of xAPI,” Megan Torrance and Rob Houck offer an overview of xAPI and provide guidance to help you get started making xAPI part of your learning management system. This issue includes: · definitions of essential terms · sample activity statements for xAPI · examples of types of data to collect with xAPI · discussion of how xAPI relates to action mapping, the Kirkpatrick model, and the 70-20-10 model · an xAPI project planning guide.