回収 and 収集: retrieving items and gathering material
Compare retrieving answer sheets or products with gathering research material or stamps. Do not restrict 回収 to return to the original distributor.
Collect answer sheets back
回収, read かいしゅう, means collection or retrieval. 授業の終わりに答案用紙を回収した。 says that the answer sheets were collected at the end of class.
This is a scene of collecting the answer sheets at the end of class. Retrieval of the sheets and their assessment results are separate information.
Gather material for a purpose
収集, read しゅうしゅう, means gathering. 研究の第一歩として地域の昔話を収集した。 says that local old stories were gathered as the first step of research.
It reports gathering research material. The material need not have been originally distributed by the same collector.
Another retrieval object
不具合のある製品を店が回収している。 says that the shop is recalling defective products. The retrieving actor and object are supplied.
Read the retrieval purpose without making return to the original distributor a universal requirement. Do not add refunds or processing obligations absent from this example.
Does 回収 require return to the original distributor in every case?
Show the answer and why
No. Read the retrieving actor and object in the scene. The original distributor or subsequent handling needs additional statements.