Search Engine Journal Says Schema Helps AI Citations. Its Own Reporting Says Otherwise

WEST PALM BEACH, FL – Search Engine Journal published an article this week suggesting that JSON-LD schema is an important technical signal for AI search visibility. But controlled testing, Google’s own documentation and even Search Engine Journal’s previous reporting tell a different story.

In “The Technical Signals AI Search Uses That Most SEOs Still Aren’t Optimizing,” Search Engine Journal places JSON-LD within its “Attribution and Meaning” layer for AI readiness and describes schema as “a vital part” of how AI understands content. The article argues that giving AI greater confidence in interpreting content can increase the likelihood of that content being cited. There is certainly evidence that schema and AI citations are correlated. But there is much less evidence that schema causes those citations.

Controlled Testing Found No Citation Boost

In May, Ahrefs analyzed 6 million URLs and initially found that AI-cited pages were almost three times more likely to contain JSON-LD. That correlation doesn’t surprise me. Websites implementing schema are probably more likely to be managed by technically advanced staff, follow better SEO practices and be better-developed websites than those that don’t. No surprise there. But that doesn’t mean schema is causing the citations. Rather than assume schema was responsible, Ahrefs conducted a second study. Researchers tracked 1,885 pages that added JSON-LD and compared them with approximately 4,000 control pages.

The results:

The increases for AI Mode and ChatGPT were statistically indistinguishable from zero. Ahrefs concluded that adding schema produced no meaningful citation increase on any platform. That is an important distinction. Websites using schema may also tend to have stronger content, better technical SEO, more authority and more backlinks, however, that just means Schema can correlate with AI citations without causing them.

Search Engine Journal Already Reported This

What makes the new article particularly interesting is that Search Engine Journal reported the Ahrefs experiment itself in May under the headline: “Schema Markup Didn’t Move AI Citations In Ahrefs Test.” SEJ reported the same results: -4.6% for AI Overviews, +2.4% for AI Mode and +2.2% for ChatGPT, with no platform showing a meaningful citation increase after schema was added.

SEJ also reported another experiment from searchVIU in which five AI systems were tested during direct webpage retrieval. According to SEJ’s coverage, the systems extracted visible HTML while ignoring information contained exclusively in JSON-LD, Microdata and RDFa. SEJ correctly noted that this does not prove schema plays no role during other processes such as indexing or retrieval. It does, however, further weaken the argument that adding schema has been demonstrated to increase AI citations.

Google Says Schema Isn’t Required for AI Search

Google’s own documentation is even more explicit. (Not that I always 100% believe them), but in its official Guide to Optimizing for Generative AI Features, Google specifically warns publishers about “overfocusing on structured data.”

Google states: “Structured data isn’t required for generative AI search, and there’s no special schema.org markup you need to add.” Google’s separate documentation for AI Overviews and AI Mode similarly says publishers do not need new machine-readable files or markup to appear in these features. That doesn’t mean schema is useless. Google continues to recommend structured data as part of an overall SEO strategy because it can help pages qualify for traditional rich results. But that is a different claim from saying schema increases AI citations.

Correlation Is Not Causation

The evidence currently supports a fairly simple conclusion: Schema markup remains useful SEO, but there is no compelling experimental evidence that adding JSON-LD makes a webpage more likely to be cited by ChatGPT, Google AI Mode or AI Overviews.

Ahrefs found a correlation and then tested whether schema itself caused the increased citations. The citation benefit disappeared. Google says structured data isn’t required for generative AI search. And Search Engine Journal itself previously reported that adding schema produced no meaningful increase in AI citations.

As AI optimization develops, distinguishing between theories, correlations and experimentally demonstrated signals will become increasingly important. For now, saying schema is useful is well supported. Saying schema increases AI citations is not.

Improving content for AI visibility is one of the most talked-about and sought-after objectives in marketing right now, which makes getting the information right especially important. I found the Search Engine Journal article particularly interesting, but after examining the research behind its claims, I also found it potentially misleading. We simply don’t have room right now for narratives that turn correlations or plausible theories into established AI optimization tactics. Marketers are already being flooded with advice about how to influence AI search, much of it based on limited evidence. Before changing strategies, spending money or implementing new tactics based on claims about AI visibility, we should demand stronger evidence and, where necessary, wait for more definitive research.

One thing I did find particularly interesting in the Search Engine Journal article, and something I had not been paying enough attention to, was its discussion of AI-specific robots.txt directives. Unlike some of the more speculative AI optimization tactics being promoted today, controlling which AI crawlers can access a website has a clear technical purpose. The article also discusses the emerging llms.txt file, which I think is worth experimenting with despite its effectiveness remaining unproven. This is one area where the article prompted me to take action: I plan to more closely review AI crawler directives across our properties and begin experimenting with llms.txt.

John Colascione

About The Author: John Colascione is Chief Executive Officer of SEARCHEN NETWORKS®. He specializes in Website Monetization, is a Google AdWords Certified Professional, authored a how-to book called ”Mastering Your Website‘, and is a key player in several online businesses.