From Roger Phillips' AKA Sweatnbullets' ""All About Aiming" and Being "Inclusive" at WT:
Situations dictate strategy, strategy dictates tactics, and tactics dictate techniques......techniques should not dictate anything.
With these truths in mind, while working varying distances, needed precision, time pressure, position in the reactionary curve, necessity and type of movement, necessary visual input of the entire encounter, and retention considerations it is plain to see that it is not a "one size fits all world."
Here is the full sight continuum as I see it (opinions may vary and that is cool.) As individuals, I feel that we need to find out what is neccesary for us (at a personal level) to make the hits inside of the correct context of the fight.
Hard Focus on the top edge of the front sight
Hard focus on the front sight
Solid sight picture
Flash sight picture
Shooting out of the notch
Front sight only with focus on the gun
"Type two focus" Focus on the threat with a fuzzy sight picture
Front sight only with focus on the threat
Aligning down the top of the slide
Metal and meat (silhoutte of the gun)
Below line of sight with peripheral vision of the gun
The last one works all the way down to "half hip." If you can see your gun in your peripheral vision your brain will use that information to help facilitate your hand/eye coordination.....whether you want it to or not. That is what the brain, eyes, and body does.
There is also body indexed firing position with zero visual input on the gun.
There are muscle memory techniques such as Quick Fire which relies on punching/driving the gun to the targeted area.
Meriam Webster's: Main Entry: ci·vil·ian Pronunciation: \sə-ˈvil-yən also -ˈvi-yən\, Function: noun, Date: 14th century, 1: a specialist in Roman or modern civil law, 2 a: one not on active duty in the armed services or not on a police or firefighting force b: outsider 1, — civilian adjective