P25-P75 range
The P25-P75 range is the span between the 25th and 75th percentiles of a set of readings: the middle half of the values, with a quarter of readings below it and a quarter above it.
Example
Ten daily readings of a brand's visibility, sorted, are 20, 22, 25, 25, 27, 28, 30, 31, 34 and 40 percent. The 25th percentile is about 25% and the 75th about 31%, so the middle half of the readings falls between roughly 25% and 31%.
Why it matters
The width of this range is what statisticians call the interquartile range. Because AI answers vary from run to run, a single number can suggest more certainty than the data supports. A range shows how stable a reading is: a narrow range means the readings cluster tightly, while a wide one means any single reading should be treated with caution.
Percentiles are less affected by one unusual reading than an average is. When two ranges overlap heavily, the difference between their middle values may not be meaningful, which is a useful check before reacting to a small change.
How Stellarcast handles it
Visibility and share-of-voice figures in Stellarcast are shown with a P25-P75 range once there are at least two days of readings, computed per engine and per market by redrawing the days behind each figure many times and taking the middle half of the results. The range shows how much the figure could still move, and it narrows as more days accrue. These are percentiles, not standard errors.
See how AI describes your brand
Get a free AI visibility audit across ChatGPT, Gemini, Perplexity and Google AI Overviews and see where you stand against your competitors.
Get your free visibility audit