収集

1. Origins, structure, and basic meaning

• Structure: 収集（しゅうしゅう） means collecting material or objects.
• Basic usage: Mark what is collected with を, whether gathering research material or collecting stamps as a hobby.

2. Common pitfalls and similar expressions

• Collecting versus retrieving
  • 収集 focuses on gathering material or objects from various places.
  • 回収 is used for taking back distributed items or gathering things designated for collection.