The Segmentation Principle basically states that small replayable segments are better for student learning than one continuous whole. By replaying the more difficult sections the user is able to utilise his time better. Here we have designed a "visually and semantically indexed scrollbar" that cues the learner to the conceptual boundaries for replayable segments. This key word and key image search may reduce the time taken to find the material to be revised.

In the version at left, clicking on the scrub bar reveals the otherwise faded thumbnails and keywords. The fading is to avoid distracting the learner's attention from the main content. This use ofvisual cues (the thumbnails below the bar) are not only for the image search: they are also a brief summary of the content that may help orient the learner and reinfoce the key learning objectives in the material.