史料 and 資料: The shared reading しりょう and their reference targets
Compare an old letter preserved for local history with presentation materials and information attributed to data.
Sources used to study local history
史料（しりょう） means a historical source. 「古い手紙を地域史の貴重な史料として保存した。」 means “We preserved the old letter as a valuable source for local history.” The old letter is preserved as a source for local history.
「複数の史料を比べて当時の暮らしを調べる。」 means “We compare several historical sources to understand life at the time.” Distinguish the sources compared from the past life being investigated. A method of comparison does not establish every research conclusion as already verified.
Materials for a presentation and attributed information
資料（しりょう） can mean materials or data. 「発表に必要な資料を一つの箱にまとめた。」 means “I gathered the materials needed for the presentation into one box.” Gathering materials does not itself report completing the presentation.
「この資料によれば、二つの案には共通点がある。」 means “According to this data, the two proposals have something in common.” この資料によれば attributes the common point to this data. It does not state that the proposals are identical in every respect.
A shared sound with a contextual spelling
Both words are read しりょう. 史料 highlights a historical source; 資料 highlights reference materials for a presentation or examination. The sound alone does not select the spelling.
A local-history letter can also serve as reference material. Rather than making the words mutually exclusive objects, read whether the sentence emphasizes the historical-source role or a general reference role.
Can the sound しりょう alone determine whether to write 史料 or 資料?
Show the answer and why
No. An old letter preserved as a source for local history is 史料; presentation materials or information attributed to data use 資料. Their reference functions can overlap, so read the contextual focus.