You type one character, and the thing scampers off like a rabid squirrel, hogging the CPU, so that the UI becomes unresponsive to me typing the remaining characters.
If you just prioritize the interactive response, the algorithm is almost moot.
When the user types m, you could as well show a completely random selection of 20 things that start with m. Or nothing. Take your time; the user will type more stuff.
When there are enough characters of context so that the selection is pruned down, there you need to be responsive. The user starts to see meaningful things in the list. When they type another character to refine it, they want it updated instantly.
Completion that is too eager is exactly like a person who doesn't wait for you to finish talking, jumps to conclusions about what you're going to say and starts replying.
Here is another thing I hate: when I see a completion I like that is itself not complete, let me continue! Sometimes the completion gives me the word I was going to type, but there is more; i.e. I wanted just to complete a part of my typing, not to choose that item as the result of the query.
I find myself manually typing the word I see in the completion list, because I know that if I click on it, it will search for that, which is not what I want.
The completion should always go into the query box, where the user can refine it before submitting it. Or at least make it an option.
It doesn't actually cost an extra click. All it means that if I use down arrow to go into the completions, the currently selected completion is copied to the query box. Then I can type more characters, or hit Enter to dispatch the query. If all I want is to dispatch the completion, it's the same number of keystrokes: down arrow to pick a completion, then Enter.
Do not have it so that when I hit down arrow, the text I typed stays the same, so that the only choice I have is to hit Enter to dispatch "microsoft" or else continue my original text from "micr". Maybe I want the word "microsoft" and then continue typing " teams" or whatever.
You type one character, and the thing scampers off like a rabid squirrel, hogging the CPU, so that the UI becomes unresponsive to me typing the remaining characters.
If you just prioritize the interactive response, the algorithm is almost moot.
When the user types m, you could as well show a completely random selection of 20 things that start with m. Or nothing. Take your time; the user will type more stuff.
When there are enough characters of context so that the selection is pruned down, there you need to be responsive. The user starts to see meaningful things in the list. When they type another character to refine it, they want it updated instantly.
Completion that is too eager is exactly like a person who doesn't wait for you to finish talking, jumps to conclusions about what you're going to say and starts replying.
Here is another thing I hate: when I see a completion I like that is itself not complete, let me continue! Sometimes the completion gives me the word I was going to type, but there is more; i.e. I wanted just to complete a part of my typing, not to choose that item as the result of the query.
I find myself manually typing the word I see in the completion list, because I know that if I click on it, it will search for that, which is not what I want.
The completion should always go into the query box, where the user can refine it before submitting it. Or at least make it an option.
It doesn't actually cost an extra click. All it means that if I use down arrow to go into the completions, the currently selected completion is copied to the query box. Then I can type more characters, or hit Enter to dispatch the query. If all I want is to dispatch the completion, it's the same number of keystrokes: down arrow to pick a completion, then Enter.
Do not have it so that when I hit down arrow, the text I typed stays the same, so that the only choice I have is to hit Enter to dispatch "microsoft" or else continue my original text from "micr". Maybe I want the word "microsoft" and then continue typing " teams" or whatever.