Structure Changes More Slowly Than Look-and-feel

Jeremy Burge on Twitter:

This comparison offers a great illustration of a design principle we covered in the fourth edition of the polar bear book: structure changes more slowly than look-and-feel.

Visually, these two screenshots look quite different. But they express the same conceptual models: a file/folder metaphor (and object-container relationship), windows that set aside portions of the display, a menu across the top of the screen (with the same menu items, even), etc. These structural constructs have endured for decades.

However, their presentation has changed as technologies and public tastes evolved. The original Macintosh featured a 512 x 314 pixel black-and-white display, which imposed many constraints on the system’s visual style. As computer displays became more capable, designers had more leeway with the presentation layer. This is the system in the early 2000s:

Mac OS X Aqua user interface.
Screenshot from Wikipedia.

Again, very different visually — but the underlying structure is recognizable. A user from 1984 would have little trouble learning the newer version three decades later.

As I’ve mentioned before, digital products don’t change uniformly; they manifest pace layers. Changing visuals is cheap; changing the underlying structures is expensive. Users accept visual changes more readily than structural changes. As a result, designers and stakeholders must take greater care when changing the structure of digital products.