Introducing User-Centered Systems Design - Foundations for Designing User-Centered Systems - page 5

Fig. 1.2 Rank order the
quality of these stove burner
to knob pairings. If layout
1 will give 100 errors, how
many errors will the other
pairings lead to? Adapted
from Chapanis and
Lindenbaum ( 1959 )

Ratio of Errors

Layout 1

@ £

100

% &

% @ & £

Ratio of Errors

Layout 2

@ £

% &

@ % £ &

Ratio of Errors

Layout 3

@ £

% &

@ % & £

1.2.2 Designing Stove-Top Mappings

For our second example, take a look at the stove-top designs in Fig. 1.2 . Which is
the best burner to control knob mapping? If you think you know the best mapping,
can you provide a quantitative measure of how much better? If layout 1 has 100
errors for a given amount of use, how many errors will the other two have?
For the examples in Fig. 1.2 , only four out of 53 subjects selected the correct
order of layout to be layout 3 (76 errors per 1,200 trials), layout 2 (116 errors per
1,200 trials), and then layout 1 (129 errors per 1,200 trials), and only 15 out of 53
could correctly identify the best design.