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1.5 The goals of interaction design 15

kind of user in any kind of situation avoid the dangers of carrying out unwanted ac-
tions aceidentally. It also refers to the perceived fears users might have of the con-
sequences of making errors and how this affects their behavior. To make
computer-based systems safer in this sense involves (i) preventing the user from
making serious errors by reducing the risk of wrong keyslbuttons being mistakenly
activated (an example is not placing the quit or delete-file command right next to
the save command on a menu) and (ii) providing users with various means of re-
covery should they make errors. Safe interactive systems should engender confi-
dence and allow the user the opportunity to explore the interface to try out new
operations (see Figure 1.6a). Other safety mechanisms include undo facilities and

Color Settings b

lb)
Figure 1.6 (a) A safe and an unsafe menu. Which is which and why? (b) Warning dialog
message from Eudora.