Case Study: Expert Evaluations of Complex UIs - Cross-Cultural Human-Computer Interaction and User Experience Design - page 58

FIGURE 4.11 Adobe Photoshop healing process. Source: Adobe Photoshop CS2. Adobe
product screenshot(s) reprinted with permission from Adobe Systems Incorporated.
(5) Drag the pointer (brush) over the object to eliminate. Repeat several times
until the object is canceled. (Every time the mouse button is released a dialog
appears with the healing progress bar.)
(6) Save changes to the file.
HE analysis
Direct manipulation/see and point; error prevention.
Although the users can use the tool directly on the image, they are 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 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.
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. Adobe Photoshop is meant for
professionals. This distinction of audience is manifested implicitly by the channel
of distribution (commercial software) and explicitly in the marketing documentation
(Adobe Photoshop's slogan reads: “The professional standard in desktop digital imag-
ing” (Adobe, 2005)). The menu paradigm is constructed by combining noun-verb or
verb-noun items, which seems deliberate (only one model should be chosen.) A more
specific audience for this function is photographers and advertising designers.