align with expectations: keyboard layout (!@# on 123 for US keyboards, abc on 2 for NANP dial pads, but comply with localization always!);

Problem

Text and numeric entry must be easy, and be able to be performed with little or no instruction.

Solution

The typewriter or computer keyboard, and the telephone keypad, have become so ubiquitous that they are, to most populations, the expected method of entering information, even when simulated by membrane pals or on a screen.

will stay that w? for the foreseeable future....

good input all about meeting expectations... see notes about kb layout, NANP, localization...

Variations

instead of variations, axes of variation, which can be combined. NOTE: Most devices will here multiple modes... see input mode pattern

Hardware / Virtual

keyboard / keypad

Direct / Multi-tap

Note that predictive systems, while associated with 10-key entry, can be uses with any input method, and is addressed in a separate pattern.

Interaction Details

Hardware keys should comply with Human Factors standards for pressure, size and spacing...

Software, 10 mm spacing

The layout and key arrangement should, whenever possible, use common and expected formats. For keypads, use regional standards promulgated by the local telecommunications authorities. In North America, for example, this does not just mean the layout is

Keyboards may have to be compressed, and combine the number row with the top row of letters. Make sure the numbers align to their normal location, so Q will also be 1 when a function modifier is used. Likewise, place all conventional symbols as close as possible to their typical location. The !@#$ symbols should be alternatives of the 1234 keys -- or the closest equivalent when compressed -- for US English keyboards.

keys must perform expected behavior, note that backspace and delete are different things, and those accustomed to e.g. Windows will think "del" means "forward delete" and not backspace, so be careful with labels. For keyboards, provide an enter function as part of the return key; users may submit entries without leavingthe keypad.

key repeat

special kegs, like Sym, dotcom...

Unless hardware directional keys (which see) are included on a device, hardware keyboards should be accompanied by one...Hardware keypads are always, and usually also have Soft keys (link)

Switching language on virtual keyboards...

Presentation Details

Key labels must be clear, large enough for users to read, and easy to read in all lighting conditions. Alternative labels (shift or Fn characters) should be in a different (less prominent) color, or a tint of the primary label color. Alternative labels should be above the primary label. There is no need to display capital letters as alternative labels to lower case letters.

On virtual keyboards, use the label for the current state, to assure the state is clear. Display lower-case labels unless the caps or caps-lock key is activated.

reflective and transmissive labels must match, phones, are used in all contexts, so need to work in the dark

Some discussion of the tradeoffs in symbols for internationalization and some of these issues (del vs. backspace) and ambiguity in labels. Even the common down then left arrow is not recognized universally as a return or enter key to many users.

Antipatterns

Avoid accidental input. Lock keypads when sensors determine they are in pockets, against the user's face (on a call), etc. In any context, if multiple adjacent keys are pressed within a few milliseconds, this can be assumed to be incorrect and only the most likely key -- by physical mapping or Autocomplete & Prediction -- should be accepted, or none. Staggered keyboard layouts can also help prevent accidental inputs or increase the accuracy of filtering.

Don't use weird layouts.... unless you test it, and then have a good way to market...

Examples