Teacher Development Interactive (TDI) is an online professional development program that trains and certifies teachers to deliver effective instruction in English as a foreign language. TDI provides both a strong foundation in teaching methodology for new teachers and an effective refresher course for experienced teachers.

Each module includes interactive activities that combine text, video, audio, PowerPoints, discussion, and quizzes. Teachers are guided and supported to complete the modules through an online facilitator, an IGA trainer.

Successful completion of fourr modules leads to a First TESL/TEFL Certificate from the internationally recognized ELT Institute, Hunter College, City University of New York.