2012-03-13

Tablet Computer Issues and Touch-Screen Interface Pros and Cons

Perm URL with updates: http://xahlee.org/comp/touch_screen_interface.html

Here's my report on tablet.

This page discuss some issues of tablet computer (e.g. iPad), and its touch-screen interface advantages and disadvantages in comparison to a PC and mouse.

Recently, i got a tablet computer (BlackBerry. amazon 7″ screen, 1024×600 pixels.). (See: Modern Tablet Computer Features.) Here's some pros and cons.

• On a tablet, the feature of web technologies (unicode, video, flash, html5, webGL etc) is pretty much similar to browser on PC. Except that processor on tablet is not fast enough to support WebGL apps designed for PC. Also, Apple's devices do not support Adobe Flash.

• On PC, you have the concept of mouse hoover. On tablet, you can emulate that by touching the spot and hold it.

Many websites send a mobile version of their site when you access it with a tablet. For example, when you access GooglePlus (google's social network; plus.google.com). The usual nav bar at top, and both of the side bars are completely gone. You only see your main stream. No hangout feature.

Pros and Cons of Touch-Screen User Interface

The touch-screen is good for casual use. It isn't a good user interface for prolonged use. Although it's more intuitive and natural, but compared to a mouse, it's uncomfortable. Here's the reasons:

The tablet either requires holding it up, which tires the arms in 10 minutes (called “gorilla arms”). If placed on a table, it needs a prop to angle it around 30°. Even that, for a reading session more than 30 minutes, it tires the neck.

• Holding a hard, flat, thin, slab, in hand is uncomfortable. There's no curve. Also, your thumb often covers part of the screen, which interferes the reading and jitters the screen.

• Touching the flat glassy surface feels alien. When we touch something, we are accustomed by nature to feel different textures, shapes, temperature, and usually the surface will yield (e.g. use finger to draw on sand.).

• Fat finger syndrome. For 7″ tablets, the screen is often too small for touch to be accurate. Often, you have to make several tries. Very annoying.

• With mouse, you have hover concept. For example, hover mouse point on some items to have definition pop-up. With touch interface, you have to hold over. Very clumsy and slow.

• Scrolling is also much easier by scroll wheel than finger swiping on screen. Swiping over the screen feels un-natural and uncomfortable.

• For anything that involves typing text (such as writing email, programing), on-screen keyboard is extremely painful to use. Speech recognition today solves most of this problem, but not when the text isn't everyday speech. e.g. programing or any technical computing work.

Issues for Web Designers

Because the touch interface is quite different from a pointer device, UI of applications for touch device need to be re-designed (e.g. image editor, video editor, 3D editor). For less complex activities, such as web browsing, it's sufficiently similar. You could create a dedicated mobile version for your site, or, pay attention to the following points:

• Due to the UI difficulties of opening a link in new window on tablet browser, this means, for web site designers, you probably should not have all links open in own window. For some links, it's better to specify target="_blank". (i.e. open in new window on normal click).

• You should not heavily rely on hover to pop-up tooltips, because hovering is difficult on touch-screen. For example, suppose you have educational site of classical literature, and hovering pops up the definition of word' under cursor. You'll have to change that to clicks instead.

• For long documents, you probably should have links that take user to top of document. Because, on PC, the Home or mouse wheel can do that easily, but not on touch-screen.