by Dan           Miller, Macworld.com           Aug 15, 2011 9:30 am 
                     Lion’s support for gestures—tapping and swiping fingers on a       Multi-Touch trackpad—isn’t entirely new. OS X has supported       gestures in some form for several years. Even so, many of us still       haven't adopted gestures as a way of interacting with our Macs.       Maybe we don't have the right Multi-Touch hardware. Or maybe the       mouse-plus-keyboard interface is burned so deeply into our muscle       memory, we've seen no reason to switch.       
              But if Lion is any measure, gestures are becoming an important         part of OS X; someday, they might replace the mouse entirely. So         Lion's launch is a perfect opportunity to make the switch—or, at         minimum, to become conversant in this interactive language. And         even if swiping and tapping on a trackpad is already familiar to         you, you’ll still need to adjust to Lion’s new vocabulary. Here         are some tips for doing both.
       If you use gestures now
       Learning to use gestures in Lion will obviously be a lot easier         if you've already been using them in Snow Leopard. To make         things even easier, several of them haven’t changed.
                            It can also help if you use an iPhone or iPad: Several of the         gestures in Lion—including the single-finger tap, the         pinch-to-zoom, and the two-finger rotate for images—are borrowed         directly from iOS.
       If you've used any gestures before, you'll have an easier time         learning Lion's new ones than someone who has never gestured at         all. According to cognitive scientists, if you’ve trained your         brain to associate an on-screen event with some kind         of finger movement on a trackpad, it'll be relatively easy to         remap that same event to a new gesture.
       The key to learning Lion's new gestures—as well as to learning         gestures in general—is to be purposeful about it. You could pick         up gestures eventually by using them haphazardly—but you'll         learn a lot quicker if you do it deliberately.
       Here's one way to do so: Choose a gesture you want to learn and         a day when you'll start learning it. Then, on your chosen day,         stop whatever you’re doing every hour or so and spend a minute         or two repeating the gesture. Repetition is important. So is a         consistent context: If you practice for a while at the         office and then a while at home, it won't be as effective as if         you do it all at work. Repeat as necessary until you find you're         able to use your new gesture unconsciously.
                            One Lion interface tweak in particular has been giving some         veteran users fits: Apple flipped the scrolling direction. In         the past, if you swiped two fingers up in Safari, the scrollbar         of the browser moved up; the webpage itself actually moved         downward on the screen. Now, if you swipe those same two fingers         upward in Safari, the page itself moves up. For many         of us, the new scrolling direction felt at first like trying to         write with the wrong hand. But we also found that it didn't take         long to make the adjustment.
       In making the switch to the new orientation, it can help to         think of visual metaphors: It used to be that moving two fingers         up meant, “I want to view things higher on the page.” Now it’s,         “I’m pushing this page up.” Interface designers recommend         keeping such metaphors in mind as you learn; they can help your         brain map gesture to effect more quickly.
       Why learn gestures?
       If you’ve never used a trackpad, Lion’s use of gestures might         seem pointless. Why swap something that works—the trusty         combination of mouse and keyboard—for something that’s simply         new?
       To be honest, you don’t need to switch at all. Almost         everything you can do with gestures in Lion can be done with         keyboard and/or mouse.
                            But as I said up top, Apple seems intent on making gestures an         important part of the Mac interface. There are some who think         that, eventually, the Mac OS and iOS will converge, making         gestures more important still. You could stubbornly refuse to         learn gestures or even to acknowledge their existence. But         eventually that’s going to turn you into one of those people         who’s still using OS 9.
       Assuming that you're willing to join the future, how do you go         about learning gestures if you’ve never used them before? First,         of course, make sure you have the requisite hardware—a MacBook         with Multi-Touch trackpad or any Mac with a Magic Trackpad.
       The second step is to fix in your mind the benefits you’ll         accrue from learning them. I’ve spelled out some of them         above—they’re the future, you’ll be a fossil without them. But         there are more practical reasons, too. Believe it or not, some         of us have grown to like gestures—particularly when         they do as much as they do in Lion. In some ways, they simplify         the interface: You can do with one tool things that required two         (mouse and keyboard) before. And if you commonly switch between         a laptop and a desktop, you can use the same interface for both.         In other words, a trackpad could actually make you more         productive.
       My favorite rationale for adopting a new input device: New         neurons are born in our brains every day. You keep only the         neurons you use; the others die. Research indicates that         learning new tasks may help keep new neurons alive. In other         words, using a trackpad could make you smarter.
       Gestures and their metaphors
       Now that you're clear about why you're learning to use         gestures, the next step is to divide them into two groups, each         of which demands a slightly different learning strategy.
                            The first group contain those that you might call “natural”:         The effect of the gesture mimics the gesture itself. Put another         way, such gestures embody clear and simple metaphors. The most         obvious of these is the two-finger scroll (especially now that         the scrolling direction has changed); as I said before, you can         imagine that you’re pushing the page up higher on the screen         when you slide your two fingers up the trackpad. The three- or         four-finger sideways swipe to move from one virtual desktop to         another is similar: You can imagine that you’re moving one         desktop aside and pulling another one onto your screen. In each         case, there’s a metaphorical connection between what your         fingers do and what happens on the screen. The more you can keep         those metaphors in mind, the easier it'll be for you to learn.
       Among the gestures that I’d put in the “natural” class:
                - The two-finger pinch and reverse pinch to zoom in and out           (think of stretching and compressing whatever you're looking           at);
- Rotating images with two fingers (duh);
- Swiping between pages (the pages are on a horizontal band,           you're pushing one to the side to see the next);
- Swiping between full-screen apps (same deal, only with apps           and desktops);
- Spreading thumb and three fingers apart to expose your           desktop (you're flinging aside open windows to see what's           underneath).
Some people might also include the         pinch-with-thumb-and-three-fingers that summons Launchpad;         personally, I haven’t been able to come up with a metaphor for         that one. And some would include the three- or four-finger         swipes up and down to see Mission Control and App Exposé,         respectively. I haven't been able to come up with a good working         metaphor for those either; maybe you can.
       You might have your own mental images of what each gesture         does. It doesn't really matter what the metaphor is, as long as         you have one. To learn these "natural" gestures, follow the         routine described above—commit to learning, devote time to it,         then practice repeatedly—and, as with the new scrolling         direction, keep those metaphors in mind as you do.
       Unnatural gestures
       That leaves a bunch of gestures that don’t have any         metaphorical match between action and effect. Fortunately,         several of them correspond to things you’ve traditionally done         with the mouse.
                            For example, to click on an onscreen button with a mouse, you         move the cursor over it and click with a mouse button; on the         trackpad, you move the cursor over the button and click or tap         with one finger. To summon contextual menus with a mouse you         Control- or right-click; using the trackpad, clicking or tapping         with two fingers (or clicking one of the trackpad's lower         corners) does the same thing. To drag something on screen with a         mouse, you click, hold, and drag; a three finger drag across the         trackpad can do the same thing.
       In these cases, you’re remapping a single on-screen result from         a mouse movement to a trackpad gesture. As with gestures you         already knew, such remapping is easier than learning something         entirely new. To learn these mouse-like gestures, again you just         need to practice on purpose: Pick a gesture and deliberately         repeat it.
       Finally, there are those Lion gestures that have no good         metaphors and no mouse equivalents: Double-tapping with three         fingers to do a dictionary look-up, double-tapping with two         fingers to zoom, and (for some) those three- or four-finger up         and down swipes to invoke Mission Control and App Exposé. To         learn those, you'll have to rely on rote practice. They just         might take a little longer to learn than the other gestures. But         if you want to learn them, you can.
       One final thing that's important to remember: It might take         some time to retrain your fingers, hands, and brain to use         gestures, and you'll feel clumsy in the process. When you're         feeling fumble-fingered, remind yourself that once upon a time         you learned to use a mouse. There’s nothing natural about that         at all. (Remember those stories of novice users trying to move         the cursor by holding the mouse up to the screen?) Thanks to         thousands, if not millions, of repetitions, those mouse moves         are second nature to you now, while gestures feel utterly         foreign. But if you learned to use a mouse, you can learn to use         gestures, too.
       For a downloadable PDF illustrating and explaining Lion's           Multi-Touch gestures, go here.
       Thanks to Reza             Shadmehr, Wendy Wood,           and Jamie Zigelbaum           for their help with this story.