What is appreciative discrimination? It is the distinction of all that which is firmly established. Its function is to avoid any confusion or doubt.
It is an awareness which discriminates between the individual observable qualities and defects as well as between the qualities of what is under consideration. The object which has been singled out by appreciative discrimination, is threefold:
1. Positive
2. Negative
3. Indeterminate
and the individual defects and qualities of these are distinguished.

There are four logical procedures by which individual defects and qualities are distinguished:

1. Awareness of what must be done
2. Awareness of relationship
3. Awareness of attaining proper validity
4. Awareness of the absolute real
Some doubt is dispelled when certainty is attained through an investigation which derives from these four operations, the specific function of discriminative awareness is said to abolish doubt.

In cogitating their respective significance, Tsong-kha-pa states-

May the investigating mind which
Arises from thinking, day and night, about
What is before the mind, dispel doubt after
Singling out the significance of what has been heard
By means of the four operations.
The reason that the five mental events beginning with intention are here called 'object-determining' is that these mental events have each grasped the specification of the object. When they are more steady, there is certainty concerning each object.