Typing URLs on a phone keypad
Typing text on a phone’s “12key” keypad has a different metric than typing on a normal computer keyboard. Typing on a phone comes in two flavors:
- using predictive input (T9), where you only hit each key corresponding to a letter once, and the word is disambiguated based on a dictionary
- using repeated key presses to select the individual letter from the group of 3 (or more) letters associated to a key
When typing URLs a dictionary is not very helpful, because usually the URLs aren’t composed of dictionary words. This means we can’t use T9 for URLs, so we’re left with the “repeated presses” typing method.
The slowest typing situation happens when one has to type successive letters that are located on the same key. Example: typing “abac” is slow. All these letters (a, b, c) are located on the same key “2abc”. You have to make a small pause after each letter to indicate the advancing to the next letter. Were the successive letters located on different keys, no such pause would be necessary.
I’ve written a small script which computes the cost of typing a given text on a phone keypad. You enter any text and it shows a number, the cost. The smaller this number, the easier/faster to type is the text:
(by the way, this is the first Javascript code I’ve ever written)
For example, here are some text fragments, with their respective costs (smaller cost is better):
| javia.org | 20 | |
| javia.eu | 17 | |
| com | 9 | |
| net | 5 | |
| org | 7 | |
| mobi | 11 |