執筆 and 著作: Writing in Progress, Collected Materials, and Existing Works
Compare writing a new work or collecting materials for a paper with borrowed works and later writings. Distinguish writing and preparation from the works without assuming completion or publication.
A work being written and materials gathered for writing
執筆 (しっぴつ) means writing or authorship. 「作家は海辺の宿で新作を執筆している。」 — “The author is writing a new work at an inn by the sea.” Writing the new work is in progress at the inn by the sea, without a report of completion or publication.
「論文の執筆に必要な資料を集めた。」 — “I gathered the materials needed to write the paper.” The collected objects are materials needed to write the paper. Preparation for writing does not establish that the paper was written or published.
Works borrowed and later writings
著作 (ちょさく) means a work or writing. 「図書館でその研究者の著作を三冊借りた。」 — “I borrowed three works by the researcher from the library.” The borrowed objects are three existing works by the researcher. The focus is borrowing works, rather than collecting writing materials.
「晩年の著作には故郷への思いが色濃く表れている。」 — “His later writings strongly reflect his feelings for his hometown.” The sentence concerns feelings for home expressed in later writings. It refers to content in works, rather than reporting writing in progress or material collection.
Activities, preparation, and the works referred to
新作を執筆している describes writing in progress. Gathering 執筆に必要な資料 describes preparation. Borrowing 著作 or reading feelings reflected in it refers to works in these examples.
Keep those uses distinct without making an absolute rule that 著作 can never refer to writing activity. Neither collected materials nor ongoing writing alone establishes completion or publication.
What do collecting materials for a paper's 執筆 and borrowing the researcher's 著作 each describe?
Show the answer and why
The first is preparation for writing; the second is borrowing existing works. Having gathered materials does not establish a completed paper or publication.