How it works
SigPhi answers from public-domain primary sources and preserves the link between each answer and the passages it retrieved.
Where the texts come from
The corpus brings together public-domain editions from digital libraries such as Project Gutenberg, Wikisource and the Internet Archive, as well as texts from other public repositories. The Library displays the author, work, language and editorial notes available. Biographies provide context only and are not citable sources. The texts themselves are never altered: cleanup removes only the print artifacts of scanning — page numbers, running headers, words split across line breaks — never a single word of the text, and different editions are never stitched together silently.
Splitting and indexing
Texts are normalized and split into overlapping passages so context is not lost at fragment boundaries. Each passage retains its author, work, language and authorship or completeness warnings. Search combines semantic similarity with word matching before selecting the passages sent to the model.
What “verifiable citation” means
A citation is confirmed only when its author and work match a retrieved source. A chapter or section is shown only when it appears explicitly in the text or citation; SigPhi does not infer one. Opening a chat source reveals the retrieved excerpt and a link to the work.
Languages and translations
The answer is generated in the language of the question and may translate or paraphrase a passage's meaning. In the quotation index, SigPhi provides a generated translation in the page language and shows the included edition's text immediately underneath. The generated translation is not a published edition; historical translations are identified in the catalogue.
Editions and repeated works
The same work may appear in several languages, translations, volumes or editions. SigPhi keeps them as separate records to preserve traceability. When they share a translated title, the index also displays the original title and language so they can be distinguished. When a question retrieves the same work in more than one language, the citation points to the edition in the author's own language: translations are there for the reader.
Limits and corrections
Digitized texts may contain OCR errors, incomplete metadata or imperfect divisions. Generated answers can also misread a passage. Responses can be rated with the chat controls, and bibliographic errors can be reported with the affected author, work, quotation and link.
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