The study breaks down the effect by the source's search position, and there the sign flips. For a page that already ranks first, all three methods lower visibility in the AI answer: source references by 30.3 percent, quotations by 22.9 percent, statistics by 20.6 percent.
For a page in fifth place, it is the other way round. There, visibility rises by 115.1 percent with source references, by 99.7 percent with quotations and by 97.9 percent with statistics, more than doubling. The authors sum it up as: the method helps lower-ranked pages in particular.
That is why we do not apply the process to an entire website. We first check where each page stands today and start where the study shows a gain. For pages that already rank at the very top, we measure before and after instead of rebuilding blindly.