There are a lot of folks in the community saying that implementing structured data / schema on your pages will help you with AI Search visibility. But few have really tested it until now. And those few tests show that adding structured data / schema does not help with your visibility in AI search, at least not yet.
The first to test this was Mark Williams-Cook who posted on LinkedIn an experiment he conducted where he posted a "visual explanation of why your favourite LLM does not use schema in their core training data." He explained how when the LLMs process the page, it actually "destroys" the schema markup and thus does not use it.
He wrote:
LLMs work by "tokenising" content. That means taking common sequences of characters found in text and minting a unique "token" for that set. The LLM then takes billions of sample "windows" of sets of these tokens to build a prediction on what comes next.The image below is some example schema that has a colour change applied which represents that set of characters is a unique token as made by the GPT-4o model.
What you will notice is that the schema gets "destroyed". For instance, the schema "@type": "Organization", gets broken down so there are separate tokens for "type" and "Organization", which means that in terms of tokenisation the regular words "type" and "Organization" are not distinguishable from schema.
If schema was included in this training data, all it would do in reality is say there is a slightly (likely insignificant) probability of tokens such as "@ appearing before the word "content".
Here is his screenshot:
If that is not good enough for you, Julio C. Guevara also tested it and wrote about his test on LinkedIn as well. He said "We set up two product pages of the same made-up product that both Gemini and ChatGPT had never seen before. One page had all content visible in the HTML as text + structured data, the other page had only structured data and else nothing visible as text (visually empty)."
The result show no benefit. He wrote, "We tried different extraction prompts, hundreds of times, to see if the LLMs could give back information like price, colors, SKU numbers. Surprise, surprise: this only worked on the page with information visible as text."
His test show the LLMs couldn't even see the text within the structured data.
Of course, this can all change in the future but here is some early testing done on this.
