Source Credibility
Source credibility is how much people believe a message because of who it comes from, mostly whether they think the source can be trusted. A 1951 Yale study by Carl Hovland and Walter Weiss found people learned the same facts from trusted and distrusted sources, but changed their minds more when the source was trusted.
Source: Hovland and Weiss, The Influence of Source Credibility on Communication Effectiveness, Public Opinion Quarterly (1951), checked October 29, 2026
What Source Credibility means for your business
If you're here for a class or a research paper, that's the meaning you want. A good check on any source is to ask who wrote it, what they know, how current it is, and what they want from you.
Four weeks later, the people in the study agreed with the distrusted source almost as much as the trusted one. The authors' explanation was that people kept the claim but lost track of who said it, which they linked to the sleeper effect. We'd read that as a warning for any business: buyers may remember a claim about you long after they forget it came from a stranger.
In search, the idea turns up as trust. Google's guide to its ranking systems describes reliable information systems that work to show more authoritative pages and demote low-quality ones. Our E-E-A-T entry covers how Google's raters judge trust.
If buyers keep repeating something wrong about your business that they picked up somewhere else, we'll track down where it started and work on getting it corrected.
Last reviewed October 29, 2026. All terms
How AI answers it today
On October 29, 2026, Google's AI Overview and ChatGPT both gave the research-paper meaning, with tips for judging a source. The Overview cited ScienceDirect, Cambridge Dictionary, ResearchGate, Scribbr and a library guide; ChatGPT cited nothing, and neither mentioned search.
Our run through ChatGPT and Google's AI Overview, October 29, 2026. A sample, not what every buyer sees.
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