Media & UDL: There is no "one way"
Now that you have read through all the material and completed the educational activities, you may have noticed that you do not have one succinct answer to the question: How can I make sure my course/lesson materials are accessible to all students?
There is a philosophical side to the question, for starters, and Universal Design for Learning provides a useful framework for thinking about what it means to make information accessible. As with the "accommodations" approach, is it a better idea to place the onus on learners to communicate their unique needs? Or, as the UDL school of thought suggests, is it more important for teachers and content creators to make their materials as inclusive as possible to begin with?
Once you have your stance on the conceptual side of the accessibility question, there are still more decisions to be made about the technical aspects of creating accessible materials. As W3C's alt decision tree demonstrates, how you address inclusion on a practical level is going to depend on the context: the purpose of the materials you are creating, the needs of your learners, as well as all the other materials you are including to convey information.
So even though you may be concluding this course with more questions than answers, at this point, you should be more aware of the different resources and communities available to you as you continue to learn about the technologies used to create and access digital information.