If you're interested in interactive television, particularly its history, it's hard to imagine how you won't learn a great deal from this online course.

The course (education guide) is introductory by nature and easy to understand. It has 6 sections with a whopping 600 learning points, each with one or more reference hyperlinks.

This online course itself has no questions to answer, but the exam for the diploma (example) does.

You work at your pace on this interesting, easy to understand, historically oriented online course. Most of the hundreds of topics defined and discussed are listed here.

Again, to get the diploma you must take and pass the free exam.

This course is introductory by nature and does not teach how to create actual interactive television content.  

See part of the course here.