Glue: How Google Measures Interaction with Special Search Features

01What is Glue?

Glue measures whether users interact with special Google elements like carousels, 'People also ask' boxes, or news features. It is the counterpart to NavBoost, the system that evaluates clicks from search. NavBoost measures clicks on traditional blue links. Glue measures interaction with the special elements: tapping a weather carousel, expanding a 'People also ask' accordion, or scrolling through a news box.

Together, NavBoost and Glue form a complete picture of user satisfaction. NavBoost captures the traditional search journey: query → click → stay/return. Glue captures the modern search journey: query → interact with feature → find answer without clicking → satisfied. As Google's SERP (search results page) evolves from ten blue links to rich features, Glue's importance grows.

Glue is fed by NavBoost (System 1), so both share the same behavioral data foundation. They differ in what they measure. NavBoost extracts click patterns from the organic results, while Glue extracts interaction patterns from the special features layered on top.

02Glue in the ranking architecture

Glue counts as a primary signal for two E-E-A-T dimensions: Authority (A: primary) and Trust (T: primary). This dual primacy makes sense: when users interact with a special feature containing a publisher's content, it signals both authority (the publisher was selected for the feature) and trust (the interaction validates the content).

Glue feeds into Tangram (System 3), the assembly layer that builds the final search results page. Tangram takes ratings from NavBoost and Glue and decides which results to show, in what order, and with which special features. This makes Glue a key input to SERP composition: not just a ranking signal, but a signal about how to present results.

Glue also maps to Experience (E: indirect) and Expertise (Exp: indirect) in the E-E-A-T dimension mapping. These indirect signals arise because users who interact with a feature engage with the content at a deeper level than those who simply click a link. This deeper engagement signals both experience and expertise.

03Implications for SEO practitioners

Glue creates both an opportunity and a risk for publishers featured in special SERP elements. The opportunity: interaction with your content in a carousel or 'People also ask' box signals satisfaction to Google, which can improve your rankings. The risk: if users consistently skip your content in a carousel, that signals dissatisfaction.

Rich results (carousels, FAQ accordions, news boxes) are not just display formats. They are interaction surfaces that Glue measures. For structured data, the implication is clear: a well-structured weather carousel that users tap through generates positive Glue signals. A carousel that users scroll past generates nothing.

Because Glue is connected to Tangram, Glue data influences not just rankings, but SERP composition. If users consistently interact with weather carousels for a query, Tangram will show more weather carousels for that query type. This creates a feedback loop: good interaction → more features → more interaction.

04References