The most common and most likely answer to this crossword clue is the 10 letter word DIAGNOSING
I've seen this crossword clue in The Guardian
D
I
A
G
N
O
S
I
N
G
Buddy explains!

The straight part
We know that "Identifying" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case identifying = diagnosing.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does DIAGNOSING mean?
DIAGNOSING verb- To determine which disease is causing a sick person's signs and symptoms; to find the diagnosis.
- (by extension) To determine the cause of a problem.