This has been discussed many times, just use the search function.
Modelyear 97 Adroit frames (usually in Koi, usually produced in 96) were 96 Attitudes without the integrated bottom bracket and without the brazed on seat clamp. These frames do not "deserve" the name Adroit, if you ask me.
Modelyear 96 Adroit frames (usually in Burgundy Blue) without the 2inch downtube (bumps around the holes for the bottle holder) were 100% Attitude frames. However, the 96 Adroit was available with the Strata-Fork (boron, very light).
The reason for this was Trek wanting to make more money, I guess.
Some early modelyear 96/late 95 Adroit frames still had the 2inch downtube. However, no boron/carbon were used on the frame.
Only 1991-93 Adroits (holes in dropouts) had the boron/carbon on the frame.