reading opponents

[sevens]

I have a question that is related to many poker books (2+2 and others) on tournament and cash strategy, particularly on NL and PL HE.

Basically it’s on categorising opponents. To put it simply:

How do you categorise opponents based on what you see. In tournaments and cash games you very rarely see hands to the end. If you see your opponent’s hole cards, then you can make adjustments according to what you see.

However most of the time you are left guessing. IE an opponent folded on the flop/turn to a reasonable bet. AQ5 flop he could have held a weak A or an under pair. Opponent could be bluffing. However it’s very hard to make a real decision on holdings unless hands are shown down, tournaments or cash online (as tables break early either way)

Any guidelines on how you reach decisions would be appreciated.

Regards