  Many educational organizations are employing instructional video in their
pedagogy, but there is limited understanding of the possible presentation
styles. In practice, the presentation style of video lectures ranges from a
direct recording of classroom teaching with a stationary camera and screencasts
with voice-over, up to highly elaborate video post-production. Previous work
evaluated the effectiveness of several presentation styles, but there has not
been any consistent taxonomy, which would have made comparisons and
meta-analyses possible. In this article, we surveyed the research literature
and we examined contemporary video-based courses, which have been produced by
diverse educational organizations and teachers across various academic
disciplines. We organized video lectures in two dimensions according to the
level of human presence and according to the type of instructional media. In
addition to organizing existing video lectures in a comprehensive way, the
proposed taxonomy offers a design space that facilitates the choice of a
suitable presentation style, as well as the preparation of new ones.
