Theory based design and evaluation of multimedia presentation interfaces
Multimedia (MM) Applications currently suffer from an ad hoc development process. This places the usability and effectiveness of many MM products in doubt. This thesis develops a theoretically motivated design method and tools to address these problems. The thesis is based on an analysis of the cognitive processes of attending to and comprehending an MM presentation. A design method is then developed based on these cognitive processes. The method addressesth e problem of selecting media to presenting information requirements,h ow to design the media to effectively deliver the desired content, how to combine verbal and visual media successfully, and how to direct the user's attention to particular part of the presentation. A number of studies are then presented which provide validation for the method's claims. These include eye tracking to analyse the user's reading / viewing sequence, and tests of expert and novice recall of MM and conventional text / speech presentations. A set of re-authoring studies show that application of guidelines improves retention of the content. The method is supported by a design advisor authoring tool. The tool applies the guidelines using a combination of a critiquer and expert system. The tool demonstrates that the guidelines are tractable for implementation, and provides a novel approach to providing authoring advice. Both the method and the tool are also validated in case studies with novice users. These demonstrate that the method and tool are both usable and effective.