The better Chinese input methods achieve ~3 keystrokes per character on handheld devices. [1] IIRC average word length in English is around 5 or 6, vs. around 2 for Chinese. So the input time should be about the same.

The real bottleneck isn't the actual typing, but thinking of something to type --- and it's a lot easier to think of how to say something verbosely rather than concisely!

[1] http://www.pascal-man.com/navigation/faq-java-browser/2009_S...

You're right that Chinese and English can be comparable in input time, provided that you're using something like t9 for the English.

However, you lose a ton of speed the moment that you hit a word that isn't in your t9 dictionary. Chinese input methods don't have that problem. So, the best case for English usually equals the average case for Chinese.

Of course, since texting is the primary communication mode for many young Chinese, they can usually text blinding fast in any language.

Yes, you need 1-4 keypresses per char, but the language itself is significantly more compressed than English. The equivalent of an English word is 1 to 2 chars (with more frequent words usually being one character - just as frequent English words tend to be shorter), but the number of "words" you use to express the same idea is generally fewer, primarily because the language is a lot more ambiguous than English (e.g., there is no 'the', 'a', or 'an', and subjects are often dropped - it is left to the speakers to fill in the blanks from context).

OK, you need 1-3 keypresses for English.

Ah, of course, it's tree navigation.

The number of keypresses required to enter the character is O(log(number-of-chars-in-alphabet)).

So having lots of characters is a win for input speed. Thanks.