Case Study: Expert Evaluations of Complex UIs - Cross-Cultural Human-Computer Interaction and User Experience Design - page 61

(6) Select the Clone tool (symbolized by a stamp) from the toolbox.
(7) Drag the pointer (brush) over the object to eliminate. Repeat several times
until the object is canceled. (Every time the mouse button is released the
effect is applied.)
(8) Repeat with the healing brush afterwards.
(9) Save changes to the file.
HE analysis
Direct manipulation/see and point; error prevention.
Although the user can use the tool directly on the image, he or she is reminded every
time to select a source region first. Instead of forcing the user to go “backwards,” the
program should allow the user to select the region afterwards. Such a change in the
perceived interaction timeline also violates the principle of error prevention.
Recognition rather than recall.
The healing function works of course to remove texture imperfections of the image.
The user, however, is not presented with any clue that he or she can use it also to
completely remove an object.
Match between system and the real world.
The “plaster” symbol in the real world works to cover a wound and help it to heal.
In the system it is not covering nor healing anything. It is only modifying the pixel
texture. Moreover, the interface didn't provide information to use after the clone tool.
SA analysis
Actors, audience, paradigm.
All of the objects involved in the interaction pertain to the leading paradigm of
“window, icon, menu, pointing device” (WIMP). The paradigm is constituted by the
menu bar, toolbars, main window containing the image, dialog windows, icons, and
pointer. The paradigm is bound to the GUI metaphor. GIMP is intended for ama-
teur/semiprofessionals and programmers. This distinction is manifested implicitly by
the channel of distribution (open-source) and explicitly in the marketing documenta-
tion (in GIMP it is by stating, that “[i]n the free software world, there is generally no
distinction between users and developers” (GNU Project, 2009)). The menu paradigm
is constructed by combining noun-verb or verb-noun items, which seems deliberate
(only one model should be chosen). GIMP shares the same user group as Adobe
Photoshop (photographers and advertising designers).
Symbols.
The users are addressed by symbols related to the user domain. In this case, GIMP's
icon of a stylized dog head connotes playfulness, fun, and ease of use. The icon is
not used on the splash screen, however, in favor of a planet picture. The toolbars and
other screens show larger and more colorful button icons and larger dialog windows