Human-Computer Interaction 3e Dix, Finlay, Abowd, Beale
Experiment with HyperCard or another hypertext system if you have access to one. As you work through the system, draw a map of the links and connections. Is it clear where you are and where you can get to at any point? If not, how could this be improved?
This is an experimental exercise which requires access to a hypertext system. It can be used as the basis for a practical class, in which students analyze the effectiveness of the system.
Drawing the map has two purposes: one is to reinforce the overall structure of the hypertext; the other is to test the navigational support that is available. Whether it is sufficient will depend on the system under scrutiny, but possible improvements would be to provide an explicit map, escape buttons, explicit paths to core material. The system may of course incorporate such features.
Do the same for this book's website and tell us what you think!
What factors are likely to delay the widespread use of video in interfaces? What applications could benefit most from its use?
Some of the factors are the costs in terms of hardware and software for compression and decompression; the slow speed due to the high bandwidth; the overall cost of equipment (for example, camera, video, CD); the lack of design tools to exploit video; the lack of specialist skills amongst designers. Many applications have been suggested as candidates for the integration of video. Educational systems, games and help systems are liable to benefit since information can be passed more clearly and memorably and new dimensions added. Other areas such as virtual reality can use video together with graphics in the creation of their artificial worlds. CSCW systems can use video to provide a face-to-face communication link between distributed workers (see Chapters 14 and 19). However, although these appear to be areas where video has a promising future, its use needs to be carefully considered and its consequences investigated. It may be that it will not fulfil its initial promise.
Using a graphics package such as Adobe Photoshop or Macromedia Fireworks, save different types of image (photographs, line drawings, text) in different formats (GIF, JPEG, PNG). Compare the file sizes of the different formats, experimenting with different compression ratios (where applicable), numbers of colours, etc.
ex.21.1 (ans), ex.21.2 (ans), ex.21.3 (ans), ex.21.4 (ans)