Last week, I downloaded another brand of "auto-completion" software. I tried others before, but none really appealed to me. Given that I find AutoHotKey's auto-completion feature very useful, I would expect that the kind of software that specializes in completing every word would be even more useful than software that only completes or corrects a limited number of words. But my experience does not support this hypothesis. I believe I now understand why this is so. Let me explain why I think that auto-completion software can never live up to its promise.
AutoHotKey gives you the ability to substitute easily "Best wishes, Your Name" for "bw," or almost anything else for any abbreviation or word you chose. This feature is called "auto-completion." AutoHotKey also allows you to enter a list of words you often misspell or mistype together with the correct spelling, and it will silently correct the wrong spelling. This feature is called "auto-correction. I use both extensively. Using "bw" for "Best wishes," Return, My Name" and "/bm" for inserting an HTML bookmark, etc. has become completely automatic. I don't think about having to enter these abbreviations for word, phrases, and formulae at all. I concentrate on what I want to write, not how to make it show up on screen. The same holds, of course for auto-correction. I have a tendency to type "waht." Auto-correction transforms this into "what." I don't have to worry about that mistake. This feature makes life (or thinking) easier.
In some ways this is just like touch typing or writing words by hand. If you want to write any kind of text, you concentrate on what you want to write not how you write it. When you learned to touch type or form written letters that was different. You had to concentrate on the how, but you exercised for so long that you did not have to think about the how any longer, that is, you exercised until pressing a certain key for a certain letter became automatic. The same holds for many other activities. Riding a bicycle or swimming is very much the same. You usually don't think about how you do it, but just do it. In fact, if you were to try and think about what you are doing, this would actually interfere with the actual doing of it. (This is not to say that you should never try to think about how you do something, i.e. how you actually move your arms in doing the breast stroke. Indeed, if you want to improve you must do so -- but only until you have fixed the problem and until the new habit has become automatic.)
The kind of automation that AutHotKey's auto-completion and auto-correction allows also depends on habituation. You have to concentrate on using "/bm" for a bookmark until it is automatic or has become second nature. But no longer than that. I realize how habitual this use of short cuts has become when AutoHotKey has stopped working for some reason, and "^n" does not start Notetab or "^#d" does not open the Document folder. It takes a second or so to recover from the amazement.
Now, the kind of auto-correction software I was talking about at the beginning, tries to guess every word you type. This is very difficult, as many words start out the same way. Thus "exer" could indicate that you want type "exercise", or "exertion" or "exercises". Since the program cannot know which word you will actually type, it will give you a choice of all three or more, and then make you decide by selecting the correct word, and pressing "enter" or some other key to make it appear on the screen. The program I downloaded has become very good at "guessing" what I want to write during the last few days, but it does not increase my typing speed. In fact, it seems to show it down. The reason is, I think, that I have to think not just about what I want to write, but also about how. I cannot just concentrate on putting words on the screen, but must also concentrate on the little window that suggests words in order to see whether the one I want has appeared already. This is distracting. It breaks my concentration on what I want to say and thus interferes with my thinking, which ultimately slows me down more than typing the few characters that I save in this way.
You might ask why the selection of the word cannot become "automatic" in the same way as typing and substituting a shortcut for a word or a phrase. It cannot, because it takes a decision to select the words. In riding the bike, you decide on which direction to take, or how fast you want to ride, not how you do it. Similarly, in writing I want to concentrate on what and how I say something, not on how I type it. This is why I have given up on universal auto-completion. It complicates things.