Loudly bellowed at a set of stats to crunch (3,4)
I believe the answer is:
raw data
'loudly bellowed at a set' is the definition.
I can't judge whether this definition defines the answer.
'stats to crunch' is the wordplay.
'stats' becomes 'data' (I've seen this in another clue).
'to' means one lot of letters go next to another (I've seen this in other clues).
'crunch' becomes 'raw' (I can't justify this - if you can you should believe this answer much more).
'data' after 'raw' is 'RAW DATA'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for raw data that I've seen before include "unchecked stats" , "unchecked information" , "information being analysed?" , "What statisticians must work on" .)