Source of personal information has to improve, as a rule (9)
I believe the answer is:
generally
'as a rule' is the definition.
(thesaurus)
'source of personal information has to improve' is the wordplay.
'source of personal information' becomes 'gene'.
'has' is a charade indicator (letters next to each other).
'to improve' becomes 'rally'.
'gene'+'rally'='GENERALLY'
(Other definitions for generally that I've seen before include "In most cases, usually" , "In most cases, as a general rule" , "most of the time" , "as usual" , "Usually, as a rule" .)