[thaumasiotes]

> Thus, learning Mandarin by reading requires first memorizing hundreds or thousands of words, before you can even know where one word ends and the next word begins.

That's not true at all; you can go a long way just by clicking on characters in Pleco, and Pleco's segmentation algorithm is awful. (Specifically, it's greedy "find the longest substring starting at the selected character for which a dictionary entry exists".)

Sometimes I go back through very old conversations in Chinese and notice that I completely misunderstood something. That's an unfortunate but normal part of the language-learning process. You don't need full comprehension to learn. What would babies do?

[wonnage]

That's not terrible for a dictionary where you control what you're looking up. I found poor segmentation to be way more annoying when trying to do stuff like selecting words for highlighting on my Kindle - it invariably breaks up a chengyu or selects nonsensical groups of words. Same with the Mac 3d touch quick look.

[thaumasiotes]

But that's the same interface every time. You select a character and a lookup pops up. The Pleco controls are "touch a character to pop up an entry", "move end of selection window left", "move end of selection window right", "jump to previous 'word'", and "jump to next 'word'". The popup will display an entry for whatever is the longest prefix of the selection window that has an entry. How do your touch interfaces differ?