Anthropometrics: Important Aspects of Users’ Bodies - Foundations for Designing User-Centered Systems - page 74

3.7 Exercises

3.1 Consider a smartphone, either a specific one or a composite, general one.
Attempt to come up with a trade-off function between a set of features (which
you create) and weight. Describe how to choose a reasonable point on that
curve. Is your smartphone more like a phone, tablet, or laptop?
3.2 Choose an existing interface and make five suggestions how touch could
change or improve its usability. Interfaces where this is easy to do include
CAD/CAM systems and data mining systems. Interfaces that are more difficult
include online learning environments and simple web sites.
3.3 Describe five systems where anthropometrics make a difference. To get you
started, consider small systems for playing music, and also consider how these
systems can be integrated with other capabilities (e.g., cellular phones).
3.4 Write a short report on the quality of your own desk and work area. Compare
it with an ergonomically suggested design as well as with what is available in
the place where you use a computer for study or work purposes.
3.5 Compute the constants for Fitts' law based on a thumb. This can be done by
creating a set of targets for the thumb and measuring the time for the thumb to
move to those targets. In the case where video analysis is not available, a
useful approach is to have the thumb move to the target multiple times and
then move back, or to type in a series of actions and then use linear regression
to compute the best predicted time per action. The resulting constants and
times can then be compared with other constants for pointing approaches.
3.6 Compute the time it would take to select an Eclipse menu item from the
application's top menu in Fig. 3.11 , like ''Refactor,'' and a menu from the
window's panels, like ''Target.java.'' You should compute this for the middle
of the screen (as shown) and from the actual location of the mouse pointer.
3.7 Given a 15 00

diagonal touch screen, how many buttons could you put on it?

(a) Note your assumptions.

(b) Describe how many buttons you could fit on the screen.

(c) Note any lessons you found while doing this task.

3.8 On a Penn State online course system, similar to many online course systems,
the web page shown on the top of Fig. 3.15 appears. If you click on the link
next to the pointer (Template for the Team Contract), the page on the bottom
comes up. This page notes that if you do not move the mouse over the target
phrase (blank_team_contract.doc) in 5 s, the file will automatically download
(presumably to your default download directory). It is often much better to
download into your course directory, so you have to quickly move your mouse
over the target phrase.
Comment on what would be a reasonable default time to move the mouse
using Fitts' law. Is 5 s a reasonable time, or could it be much less, or should it
be more?