Comments on: Going Mobile – Giving users the finger http://www.raizlabs.com/blog/379/going-mobile-giving-users-the-finger Mobile experience, user interface design, software and new ideas. Mon, 06 Sep 2010 08:45:19 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: graiz http://www.raizlabs.com/blog/379/going-mobile-giving-users-the-finger/comment-page-1#comment-1895 graiz Thu, 30 Apr 2009 15:13:20 +0000 http://www.raizlabs.com/blog/?p=370#comment-1895 Michael - thanks for the comment. My talk goes into this a little further. The actual mechanics of the thumb (how it hinges) actually makes it more difficult to hit certain regions of the phone even when they are physically close. A strict interpretation of Fitts law does not work. A simple example is the shutter button in the iPhone camera app. It's very hard to press because of the mechanics of your thumb, not it's size or distance. Michael – thanks for the comment. My talk goes into this a little further. The actual mechanics of the thumb (how it hinges) actually makes it more difficult to hit certain regions of the phone even when they are physically close. A strict interpretation of Fitts law does not work. A simple example is the shutter button in the iPhone camera app. It’s very hard to press because of the mechanics of your thumb, not it’s size or distance.

]]> By: Michael Zuschlag http://www.raizlabs.com/blog/379/going-mobile-giving-users-the-finger/comment-page-1#comment-1894 Michael Zuschlag Thu, 30 Apr 2009 13:33:22 +0000 http://www.raizlabs.com/blog/?p=370#comment-1894 Small nitpick: I’m pretty sure Fitts Law _does_ generally apply to mobile devices –closer targets can be touched faster than distant targets given equal target size, and larger targets can be touched faster than smaller targets given equal movement distance. Fitt’s law provides another argument for reasonably large controls for mobile apps (or any app). I think what you mean is that targets on the edge of a touchscreen do not have functionally infinite size the way they do with a pointer device UI (Tognazzini http://www.asktog.com/columns/022DesignedToGiveFitts.html). Except they do for dragging and swiping gestures. And of course, some mobile devices use a pointer device rather than a touchscreen (e.g., the trackball on some Blackberries). Yet another argument for large controls and targets is that mobile devices can be relatively physically unstable. The user may hold the device in one hand while gesturing with the other. The hands slightly move around involuntarily in relation to each other, especially if the user is walking or riding in a vehicle. Large high-contrast controls and displays are also important because mobile users often need to attend to their environment more (e.g., while walking, driving, or riding a bicycle; I’m not recommending these practices; I’m just saying I’ve seen it happen). The user needs to be able to read the displays at a glance. Keep in mind most mobile devices have backlit displays but may be used in bright sunshine so contrast can be substantially degraded. Involuntary movement of the device also interferes with acquiring small font or fine display details at a glance. Big controls. Big font. Small screen.... Big challenge. Small nitpick: I’m pretty sure Fitts Law _does_ generally apply to mobile devices –closer targets can be touched faster than distant targets given equal target size, and larger targets can be touched faster than smaller targets given equal movement distance. Fitt’s law provides another argument for reasonably large controls for mobile apps (or any app).

I think what you mean is that targets on the edge of a touchscreen do not have functionally infinite size the way they do with a pointer device UI (Tognazzini http://www.asktog.com/columns/022DesignedToGiveFitts.html). Except they do for dragging and swiping gestures. And of course, some mobile devices use a pointer device rather than a touchscreen (e.g., the trackball on some Blackberries).

Yet another argument for large controls and targets is that mobile devices can be relatively physically unstable. The user may hold the device in one hand while gesturing with the other. The hands slightly move around involuntarily in relation to each other, especially if the user is walking or riding in a vehicle.

Large high-contrast controls and displays are also important because mobile users often need to attend to their environment more (e.g., while walking, driving, or riding a bicycle; I’m not recommending these practices; I’m just saying I’ve seen it happen). The user needs to be able to read the displays at a glance. Keep in mind most mobile devices have backlit displays but may be used in bright sunshine so contrast can be substantially degraded. Involuntary movement of the device also interferes with acquiring small font or fine display details at a glance.

Big controls. Big font. Small screen…. Big challenge.

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