Apple Scrolling - Which Way is Up?

Apple Lion 10.7 has many interesting changes over it's predecessors. But one change has not received a great deal of attention, even though the issue is truly a groundbreaking one. I'll go so far as to say that in the entire history of User Interface (UI) design, it's one of the most significant changes ever.

I'm referring of course to the default setting on Apple Laptops of reversing the sense of trackpad scrolling (actually does it also reverse the scrollwheel scrolling?).

I haven't decided yet if this is a good thing or a bad thing. One could certainly make an argument that "you'll get used to it". Which is probably true - if you only use the one laptop. But if you use other laptops, older models, other operating systems, then instead of getting used to it, you're just introducing confusion. So either Apple is really confident that this is "the right way", or they've totally just jumped the shark. I think the essential issue here is what is intuitive and natural.

A lot of people may have never realized that this conflict has been sitting at the heart of UI design for decades. When you scroll through a document, are you moving the document up and down within the window, or are you moving the window up and down on top of a fixed document? When stated this way, it sounds like moving the document is more intuitive than the abstract concept of moving the window. And at this level, it's a good vote for Apple's change being the right choice. But why then wouldn't UI designers have gotten this "right" in the first place?

The problem with this model comes when you introduce a cursor into the window. In other words, for any text editor or word processing editor. At this point, the UI focus becomes the cursor. The actions you take act on the cursor, not the document or window. If you move the cursor down far enough (e.g. using arrow keys) then the document begins to move up, as the window moves down (along with the cursor). This is the reason behind the current UI standard that we've been using for decades. Down and up move the cursor (as they well should), and by extension the window, not the document. And this standard applies to windows without cursors too, as it's clearly not right to have windows without cursors operate the opposite way of windows with cursors. This model also makes sense if you conceptualize "down" and "up" relative to the content of a document. Moving "down" a document is a fairly natural thing, and people won't ususually be bothered by the fact that moving "down" within the document makes the document move up. In essence, the cursor is just the spot they are looking at as the read or skim the document. So these are all very good arguments for the model we've been using for years.

This problem existed back when the only computer interface was a terminal. The terminal was the "window", and the arrow keys operated on the cursor, causing exactly as one would expect. When graphical interfaces came about, it became possible to grab things on the screen and move them. This lead to the invention of the scrollbar. A scrollbar does serve the purpose of giving you a "handle" with which to grab and move around information within a window. But it also has served another very important fucntion, which is to clarify the whole problem that I'm talking about. New users would still show confusion about whether they were moving a document up or down, or moving up or down within a document (i.e. moving the window). The scrollbar completely solves this confusion. It represensts the entire document, and the position of the window within the document, and totally makes it clear that you are responsible for moving that window. It's no coincidence that when Apple decided to reverse all this, they also mostly got rid of the scrollbar. An ever-present scrollbar which tells you which way is up and which way is down would be a big problem when you expect people to do the exact opposite on their touchscreen (or more to the point the trackpad).

So what has changed that has caused Apple to throw this all out of the window? The touchscreen -- and perhaps the small phone-sized touchscreen in particular. With a touchscreen, one can make a pretty good argument that it becomes much more naturally to move the document, not the window. After all, you can just touch it and move it. The fact is though, the old model would work fine, as long as we stuck with a scrollbar to clarify the issue. But this is why I suggest that the phone-sized screens in particular are influencing this choice. Interacting with a tiny scrollbar on a tiny screen with big fat fingers is a really bad idea. The fact is that with touch screens we don't have the best precision pointing device. Another truth is that the vast majority of things we do on phones do not use an explicit cursor. Phones are used as consumers of information. When we put together the problem of fat fingers, with the immediacy of the touch screen, scrolling the document just by touching it and pushing it around became a fairly inevitable choice.

But it's quite a huge leap to translate this behaviour to a traditional computer GUI. For one thing, a trackpad is not a touchscreen. It's an abstraction of a pointer, just like a mouse. Because we use it to control a pointer, it's a precision pointing device, unlike our big fat fingers. And because it's an abstraction, it's unclear if "grabbing" the document and dragging it around is really the most intuitive choice.

For better or worse, this looks like one more thing that signals Apple's direction. The model they have chosen is one that fits best with a consumer device. By this, I don't merely mean a device purchased by consumer (although what I mean includes that). I mean, a device which is used to consume information, rather than produce it. You watch a movie, read a book, play a game. All the graphical, object-based things that are not related to word-processing. This is one more hint that Apple is moving farther away from being a computer company, and closer to a consumer electronics company. Is the desktop dead? And what does that mean?

I'm not even prepared yet to say if this is a good thing or a bad thing. But in light of Steve Jobs' announcement to step down as CEO, this is what we need to keep an eye on: will Apple simply abandon it's computer side of the business for the easy profits of it's successful line of iPackages? Or can it be smart enough to reinvent the entire computer UI paradigm, and provide the computer professionals with all the tools we need for all the "serious" professional work of content creation that happens on computers today?


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