Case Study: Expert Evaluations of Complex UIs - Cross-Cultural Human-Computer Interaction and User Experience Design - page 64

(5) Click-drag (to paint) several times to clone in the perspective. See the pro-
posed results in the preview.
(6) Click “OK” to apply the changes.
(7) 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.
Modelessness.
By selecting the vanishing point function, the user is presented with a new window
(named “Vanishing Point”) containing the image to manipulate and a reduced set of
controls (buttons, check-boxes, and drop-down menus). After the adjustments, the
user has to click “OK” to transfer the changes to the image in the main window
underneath. A better solution seems to be using standard controls and not introducing
a different working environment. By doing so, we would also eliminate the extra step
of applying the changes.
Recognition rather than recall.
All of the needed actions are visible and the system provides inline help. However,
the toolbar on the top-left does not show which tools are necessary for the operation
and in which sequence they should be applied.
Visible interfaces/WYSIWYG.
The vanishing point function was not present on the toolbar and was only accessible
through the menu bar. Since it is one of the advertised features, it should be as readily
accessible as possible.
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 are photographers and advertising designers.