Hypermedia: It is simply an extension of hypertext that incorporates other media in addition to text. Computer applications that present multiple media (text, graphics, animation, video) using a hypertextual organization. Operates under the logic of hypermediacy.
Hypermediacy: A style of visual presentation whose goal is to remind the viewer of the medium. One of the two strategies of remediation; the other is (transparent) immediacy.
Remediation : understanding new media by David J. Bolter
From Internet to Gutenberg by Umberto EcoSemiotic Criteria for Evaluating Instructional HyperMedia by Susan A. TUCKER and John V. Dempsey
Facilitating navigation in information spaces: Road-signs on the World Wide Web by Christopher S. Campbell
The electronic hypermedia encyclopędia: transcending the constraints of the "authoritative work"? by Patrick J. COPPOCK