I've been working on articulating some of the theory behind mobile UI
design, by examining current algorithms and heuristics from the entire
field. I'd like some feedback (blog post at ). I've got further
analysis with specific design recommendations at , but that is a
topic for a different message.
Mouse driven interfaces (software) – the "large" controls are the
edges of the screen, as they are really infinitely large in one
direction. Corners are larger still. Thus frequently used items should
go around the edges. The existence of a cursor gives a precise
definition of "close", so contextual menus can be truly context
Mouse driven web sites – when a link is activated, the screen changes,
possibly completely, and the edges of the screen are not accessible by
the web page. Thus "where the cursor is" is the largest target, and
cultural visual scanning practices are used to place most elements.
Consistency between pages helps the visual scanning process. Note:
modern web development techniques allow for an interaction style more
closely resembling software.
Stylus driven interfaces (small screens) – the concept of "distance"
is almost meaningless, as the entire screen is smaller than the hand
and there is no cursor. Thus size and predictability of location
become the key issues for speed of target acquisition.
Scroll-and-select interfaces (small screens) – the number of
keypresses to access a target is a good measure of distance, and size
is reasonably represented by whether the target is currently displayed
or not. As more devices display several font sizes, target size will
be a combination of visibility and target size.