(n,vs) investigation
examination
inquiry
enquiry
survey
(P)
(n) re-examination
reinvestigation
(n) investigator
examiner
(n) investigation department
(n,adj-no) examiner
investigator
inquisitor
agent
(n) inquiry commission
enquiry commission
research group
(n) questionnaire
(n) research division
(n) assistant (to section manager)
(n) opinion poll
attitude survey
(P)
(n) environmental research
(n) (comp) technical investigation
(n) investigation (to determine the cause of something)
(n) field survey
field work (research)
on-the-spot investigation
(n) trial record
(n) (national) census
(P)
(n) market research
(P)
(n) municipal census
(n) fact-finding
(n) factual investigation
(P)
(n) site survey
field study
(n) exit poll
(n) credit check
(n) fact-finding
(n) (col) identity or background check (often to see if someone is a burakumin)
(n,vs) examine (investigate into) a person's history
(n) (personal) background check
(n) census
(n) public opinion poll
(n) public opinion poll