Translation guide
The English word "investigation" covers a range of activities from formal police inquiries to academic research and personal fact-finding. Japanese uses different words depending on the purpose, formality, and context.
A formal inquiry by authorities (police, government) to uncover facts about a crime or incident.
The standard term for a police or criminal investigation. Used for searching for evidence, suspects, etc.
警察が事件の捜査を始めた。
The police began an investigation into the case.
捜査は難航している。
The investigation is facing difficulties.
Refers specifically to interrogation or questioning of suspects/witnesses as part of an investigation.
容疑者の取り調べが行われた。
The suspect was interrogated (as part of the investigation).
Specifically means a search (of a premises, area, etc.), often conducted under a warrant.
警察は令状に基づいて家宅捜索を行った。
The police conducted a house search based on a warrant.
Systematic study or inquiry to discover facts or principles.
General term for research or academic study. Often used for long-term, scholarly investigation.
彼は癌の治療法を研究している。
He is researching a cure for cancer.
この研究は新しい発見をもたらした。
This investigation led to new discoveries.
Broad term for investigation, survey, or inquiry. Used in academic, business, and government contexts.
Implies a deep, often philosophical or intellectual pursuit of truth. More literary.
Looking into something informally to find out what happened or to verify information.
The most common verb for 'to investigate' or 'to look into' in everyday situations.
ちょっと調べてみるよ。
I'll look into it a bit.
インターネットで調べたらすぐわかった。
I investigated on the internet and found out right away.
Means to confirm or verify. Often used when checking facts or details.
事実を確認する必要がある。
We need to investigate the facts.
To probe, explore, or sound out. Often used for discreetly gathering information.
In-depth reporting to uncover hidden facts, often by news organizations.
Gathering information for news reporting; covers interviews, research, and on-site investigation.
記者が事件の取材をしている。
Reporters are investigating the incident.
捜査 (sousa) is strictly for criminal investigations by authorities. 調査 (chousa) is a broad term for any formal inquiry, survey, or inspection (accidents, markets, etc.). 研究 (kenkyuu) is for academic or scientific research. Using the wrong one can sound unnatural: saying 警察が研究している would mean 'the police are researching' (like a scholar), not investigating a crime.
English often uses 'investigation' where Japanese would use a more specific verb like 調べる (shiraberu) or 確認する (kakunin suru). For example, 'I'll investigate the issue' is naturally 問題を調べてみます, not 問題を捜査します (which sounds like a police matter).
Report the results of the market investigation.
原因を調査する必要がある。
We need to investigate the cause.
真理の探求は科学の目的だ。
The investigation of truth is the purpose of science.
I tried to investigate his true feelings.
Specifically 'investigative journalism'.
その新聞は調査報道で知られている。
That newspaper is known for investigative reporting.