INTERACTION DESIGN PRINCIPLES FOR INTERACTIVE ...

Lamont brings up compelling advantages and disadvantages to each approach to
ITV design. However, as we have seen earlier in this chapter, overlays tend to inherently
compete with the main video content by obstructing 50% or more of the screen, and
viewers can become frustrated by trying to look through the enhancement to the primary
content. ITV interaction designers might take into consideration the fact that on the Web,
users assume that accented entities such as overlays may be clickable, leading to
additional information. While this convention is not yet popular on the television
platform, it may become increasingly transferred to iTV in the future.
When graphic content must be combined with the video screen, typically the
video portion is reduced in size and surrounded by graphics on three sides. This
commonly used format has become known among iTV designers as the “L design.” The
L design, which operates on a simple grid system, works very well provided that the
content in the enhanced area is intimately tied to the primary content of the program.
Figure 5.32 provides examples of the L design from four different applications that work
effectively to deepen the viewing experience. Each design is successful in keeping with
the colors and themes of the respective program. The enhanced content must also remain
simple and uncluttered; for example, lengthy text next to video content will be ignored by
viewers (British Broadcasting Corporation, 2002).
Common pitfalls to effective layout design include random window sizes and
arbitrary component dimensions and positioning. Figure 5.33 provides examples of these
violations. Due to the lack of a good grid system, it is difficult for viewers to know how
to focus their attention. In addition, the use of red in Figure 5.33 (b), which is difficult to
see against a black background, violates good color design guidelines for television.
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