Precise-number credibility
Specific numbers read as more factual than round ones.
Where it applies
Two of the eight page areas.
How to use it
Four ways to use it, and one to avoid.
- Write “Rated 4.7 by 2,318 customers” rather than “thousands of happy customers”.
- Use exact, checkable figures for reviews, test results and savings.
- Link each figure to its source.
- Expect less effect on sceptical or expert shoppers.
- Avoid: invented or unsupported numbers, which are unlawful under the DMCC Act 2024.
What the research found
Precise numbers made a company seem more competent, except to sceptical, informed readers.
People assume a claim with a sharp number is based on research rather than an estimate.
Schindler and Yalch found people assume a claim with a sharp number is based on research rather than an estimate. Xie and Kronrod found precise numbers made a company seem more competent, but not among sceptical readers who knew the subject. All evidence is from lab studies, mostly of advertising claims.
Key research
Three sources, each checked.
Last reviewed
Schindler & Yalch (2006) It Seems Factual, But Is It? Effects of Using Sharp Versus Round Numbers in Advertising Claims Advances in Consumer Research Read the source Xie & Kronrod (2012) Is the Devil in the Details? The Signaling Effect of Numerical Precision in Environmental Advertising Claims J. Advertising Read the source Jerez-Fernandez, Angulo & Oppenheimer (2014) Show Me the Numbers: Precision as a Cue to Others' Confidence Psychological Science Read the source
Before you use it · UK law
Figures must be true, current and backed by evidence you hold. Invented or unsupported numbers and fake reviews are unlawful under the DMCC Act 2024, and the ASA expects advertisers to hold proof for objective claims.
This is simply a pointer to check, not legal advice. Seek legal advice before you put this principle into action.