INTERACTION DESIGN PRINCIPLES FOR INTERACTIVE ...

applications based on the television, iTV applications must be navigable using only a
remote control, with the four directional arrow keys and a select key. With the navigation
limited in this way, designers must take special care in the arrangement of navigable and
selectable objects on the screen. For example, it may be a good idea to group functional
buttons into one column and navigational buttons into another. Thus, moving from one
group to the other requires only one click to the left or right. The BBC is a bit more
constrictive and actually recommends that designers limit navigation to only one axis –
either forward/back or up/down (British Broadcasting Corporation, 2002).
In general, iTV designers should minimize the number of clicks that the user must
press in order to navigate through the application. As well, these activities should not take
the user too far away from the primary screen. According to research conducted by See &
Woestendiek, environments with a depth greater than four often become disorienting and
confusing to the user (1987). Taking users too far away from the primary screen increases
the chances that they will become distracted or frustrated with the application.
Dale Herigstad, who designed the interaction for the Queer Eye for the Straight
Guy prototype at the 2004 AFI workshop, explains that his design purposefully attempted
to move away from “the ‘page model.’ As illustrated by Figure 5.41, instead of clicking
from page to page, the design keeps you in one kind of space, but one that is fluid, so that
you click one thing and it generates something else. The design is all about transition”
(quoted in Swedlow, 2004b). In another one of his designs, Woodrow Wilson, the
timeline-based navigational structure that persists along the bottom edge of the
application ensures that users never navigate outside of the iTV space or away from a
familiar point (see Figure 5.42).Yet a third tactic may be to employ the picture-in-picture
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