Skeuomorphs in UI design refer to interface elements that retain obsolete visual or behavioral aspects of the physical objects they are based on. Take for instance the bumps in the
J keys on the iPad virtual keyboard which serve no particular purpose. They are just artifacts of physical keyboards where similar indentations help provide sensory feedback to touch-typists.
Skeuomorphism is nothing new at Apple. They have been alienating users on several occasions, the most recent of which involves the redesigned iCal and Address Book in Lion. The two apps sport a new skeuomorphic look heavily borrowed from their iPad sister apps, Calendar and Contacts.
The iOS-inspired interface came under harsh criticism, dismissed as an unnecessary gimmick and mocked for being hideous and infantile. While these reactions might be disproportionate, they are not unfounded. Here is why:
False affordance. Users may expect the skeuomorph to mimic the behavior of the original object in a particular situation. Failure to meet these expectations will result in frustration and discomfort. Try as you might, there is no way of browsing contacts by manually turning pages in the new Address Book, even though the interface strongly hints at the possibility of this interaction.
Visual noise distracts users and negatively affect their productivity. Skeuomorphs are greedy for both screen real-estate and users’ attention, on the expense of efficiency and usability. The stitches in the iCal navigation bar illustrate this point.
Functional limitations dictated by the original object may severely harm the user experience. The lack of a convenient three-pane view in the new Address Book is a perfect example.
Disorienting users as a result of using an alien language that does not take advantage of the experience acquired through prior interactions with standard interfaces.
Alienating users with an excessive emphasis on aesthetics.
Then again, it’s not all doom and gloom for skeuomorphic interfaces. Their playfulness may have a more powerful emotional impact on users; a contact management app that looks like an actual address book has more chances of establishing an emotional bond with its users and engaging them on the long run. Its distinctive personality might not always favor productivity, but that would be perfectly okay for the average user. The very tone of Apple’s marketing is primarily emotional, and the skeuomorphic interfaces on both on iOS and on OS X perfectly serve their agenda.