Moreover, there are technical problems or incompatibility, when it is not possible to have the required technology, or it is not possible to obtain materials in alternative formats. Moreover, MOOC environments typically contain a variety of components that do not always share a consistency of interface logic or interactive elements, ranging from posts in a forum, making up elements in tests or timed quizzes through playing embedded videos or downloading a variety of document formats. Video lectures are key elements in the MOOC model, and the hurdles of interacting with the platform or content should be minimized. -However, alternative accessible formats, subtitles, and/or sign language interpreters for audiovisual materials, audio-description recordings are not easily available even though there exist great guidelines, such as Sánchez (2013).[32]