53. APPLICATION TO NUI multi-touch input provides significant advantages to gesture design. By deeply understanding a model for how gestures are designed, we will be better equipped to build not just individual gestures, but a set of gestures that are both consistent and error-free.멀티
97. LESSONS FROM THE PAST: AMBIGUITY put a single finger down on a piece of content and move it on the screen. While this might make for a simple UI, it severely limits the set of possible gestures and can lead to ambiguity.화면의
121. LESSONS FROM THE PAST: AMBIGUITY Let’s build up a theoretical gesture language, beginning with a possible delete gesture: To delete something, we’ll flick it to the left side of the screen.가상으로
137. LESSONS FROM THE PAST: AMBIGUITY Stages of out theoretical delete flicking gesture Registration : 1. Place finger on an item 2. Flick to the Left Continuation : None Termination : Lift the finger from the surface of the device가상으로
153. LESSONS FROM THE PAST: AMBIGUITY The first is that there is no continuation phase of this gesture the system doesn’t know it’s a flick to the left until the user has flicked, and there is no next step.이
176. LESSONS FROM THE PAST: AMBIGUITY This isn’t surprising, since the delete command has no parameters— there isn’t more than one possible way to delete something.삭제
252. LESSONS FROM THE PAST: AMBIGUITY Second, error probability is also increased if the second step has too small a space relative to other gestures (e.g., if flicking in another direction leads to another action—or worse, if sim- ply moving something, rather than flicking, is a gesture)두번째
308. LESSONS FROM THE PAST: AMBIGUITY Third, it requires an explicit mechanism to transition between registration and continuation phases: if flick right is “resize,” how does the user then specify the size?어떤
346. LESSONS FROM THE PAST: AMBIGUITY Either it’s a separate gesture, requiring a modal interface, or the user will keep her hand on the screen and require a mechanism to say “I am now done registering; I would like to start the continuation phase.”modal
368. LESSONS FROM THE PAST: AMBIGUITY Last, the system cannot respond to the user’s gesture in a meaningful way until the registration step is complete, and so this prolongs this feedback.시스템은
383. LESSONS FROM THE PAST: AMBIGUITYLet’s considera system thatimplements justfour gestures
384. LESSONS FROM THE PAST: AMBIGUITYOne finger down- ambiguousspeed,directionregistrationphase.
385. LESSONS FROM THE PAST: AMBIGUITYrename gestureThe simplest approach is for the system to assume that each gesture is a “move”until it knows better.This is good, - because the user gets immediate feedback.It’s bad, however, - because the feedback is wrong:the system is showing the feedback for the “move” gesture,but the user is actually performing a “rename” flick;
386. LESSONS FROM THE PAST: AMBIGUITYmove gestureproviding no response until the user’s action is clear.This would correct the bad feedback in the “rename” case,but consider the consequence for the “move” case
387. LESSONS FROM THE PAST: AMBIGUITY this too is a problem The system does not provide the user with any feedback at all until it is certain that the user is not performing a flick. The problem is ambiguity: because we have overloaded one-finger sliding with a large number of possible gestures, the recognizer can’t tell us quickly enough which one is being performed.시스템은
406. Solving AmbiguityThe goal, ultimately, is to avoid thetime during which the user’sintention is ambiguous.
407. Solving Ambiguity Multi-touch gives us a solution. By allowing us to move registration up to the moment of contact, set of possible gestures without increasing the possibility of error등록을
419. Solving AmbiguityiPhone gesture language : move andzoom
420. Solving Ambiguity The beauty of a multi-touch system is immediately apparent: The gestures are disambiguated not only by the movement of the contacts on the device, but also by the posture of the hand (in this case, how many fingers are touching).멀티터치
448. Design GuidelinesMust Minimize the number of steps - the user must take before in order to register the gesture mode Minimize overlap in the initial action Minimize the load required to transition - between registration and continuation phases. Provide clear feedback -for the user at each step, ensuring she understands when she has transitioned from registration to continuation, and how to terminate the gesture.
449. Design GuidelinesShould Map registration to the moment the user makes contact with the display Map termination to the moment the user breaks contact with the display.
450. Design GuidelinesCould Take this to a logical extreme, and register only based on the number of fingers. This approach is called a “chording gesture,” similar to playing a piano.
451. SummaryGesture registration is perhaps themost important step to design.등록단계에서