In this article, we will explore the lesser-known or ‘shadow’ side of Google Core Updates. In the realm of search engine optimization and digital architecture, Google Core Updates are pivotal events that significantly alter the “game rules” of search. We delve into the lesser-known components of these updates—specifically Navboost, Glue, and the Information Satisfaction Score (IS)—to uncover how they collaborate to refine and enhance Google’s search capabilities. “What is behind the scene?” It is a perfect question. Let’s start!
Background:
Core updates by Google are not just incremental changes; they are comprehensive overhauls designed to improve the accuracy and efficiency of the search engine. While many focus on the immediate impacts of these updates, such as changes in website rankings, the underlying adjustments to systems like Navboost, Glue, and IS are where the real transformation occurs. These systems are intricately linked, each playing a crucial role in how information is processed and presented to users.
As I see it, core updates are essentially a refinement of the underlying architecture of a system. It’s like a tune-up for a car – you’re not changing the fundamental design, but you’re making adjustments to ensure it runs more efficiently and effectively. By tweaking how the systems process signals and interact with each other, you’re allowing them to adapt to new data and produce more accurate results.
In my humble opinion, this is a crucial aspect of system maintenance, as it enables the system to stay relevant and effective over time.
I think what’s fascinating about this process is that even without explicit updates, the systems themselves can still evolve and improve through the influx of new data. By continuously processing fresh inputs, the system is able to refine its understanding and produce more accurate results.
Let’s talk about Google’s “secret souse”!

Navboost, Glue, and IS are integral components of Google’s search architecture, playing distinct yet interconnected roles in improving the search results presented to users.
What is Navboost?
Navboost is a system designed to enhance the search experience by utilizing data on user interactions with search results, specifically clicks. The target is user behaviour on the SERP and determining the quality of search results.
This system compiles user click data and incorporates feedback from human evaluators to refine and improve the ranking of search results.
Essentially, Navboost focuses on learning from user behavior to determine which search results are most relevant and should be ranked higher, thereby directly influencing the effectiveness of search result rankings.

Glue algorithm
Glue functions within the framework of Google’s Tangram system, which assembles the Search Engine Results Pages (SERPs).
Glue is tasked with the organization and presentation of data, ensuring that the search results are not only relevant but also well-structured and user-friendly.
This includes the placement and presentation of various elements like image carousels and direct answer boxes, making sure that the information is accessible and useful to users.

IS (Information Satisfaction Score)
The IS Score, particularly the IS4 and its derivative IS4@5, plays a critical role in measuring and ensuring the quality of search results. Derived from human evaluator ratings, the IS Score serves as a primary indicator of search quality.
Evaluators assess search results anonymously, comparing Google’s performance against competitors like Bing.
This metric is vital for training and refining Google’s search algorithms, including the systems that rely on user feedback and interaction data.
Interaction Between Navboost, Glue, and IS Data
Integration and Feedback
Navboost enhances search result rankings based on user interactions and quality ratings, which likely influence the IS Score evaluations.
As these scores reflect the quality of search results, they feed back into refining systems like Navboost and Glue.
Result Organization and Presentation
While Navboost focuses on which results are most relevant based on user behavior, Glue organizes these results effectively on the SERP.
The effectiveness of this organization can impact user satisfaction and subsequent IS Scores.
Continuous Improvement to Google Core Updates
The IS Score, influenced by real-world user feedback and evaluator ratings, helps Google identify areas of improvement not only in search relevance (impacted by Navboost) but also in how information is presented (managed by Glue).
The IS Score is pivotal in how Google manages the overwhelming amount of content and interaction it has to sift through to optimize user experiences on the web. This scoring system is not only reflective of user satisfaction but also plays a critical role in shaping Google’s algorithms.
For instance, a high IS Score suggests that a site is meeting the expectations of its users, which, in turn, influences how highly Google values such sites in search results. This can lead to a beneficial cycle, where better IS Scores result in higher search rankings, which then lead to more user traffic and potentially higher scores, provided the user experience remains positive.
I think that now we talk about the most interesting aspects.
Interaction with Ranking Systems
The data and insights from Navboost and IS Scores feed into various ranking systems like RankBrain, SpamBrain, Helpful Content System, and MUM (Multitask Unified Model).
These systems use the data to adjust how they process and prioritize information.
Sometimes we update how a particular system operates. That’s typically what a “core update” is about. We’ve made notable changes to one or more core systems, in how they process signals, weigh things up, interact with each other. It’s like a coding update.
Then the systems themselves, they’re running. They’re taking in new data. They’re understanding “hmm, I’ve got fresh inputs that I’ve churned, let me process that” and the results can change not because the system has been updated but what’s going into the system is refreshed.
Google’s search systems, including Navboost and IS (Information Satisfaction), interact with the periodic core updates quite well.
Here’s a more detailed look at each step in the process based on the information available:
Data Collection and Dataset Formation
Navboost collects user interaction data, specifically how users click and engage with search results. This data helps infer the relevance and usefulness of the results based on real user behavior.
IS Scores, derived from human evaluators, assess the quality and satisfaction of search results. Evaluators rate the usefulness and relevancy of search results, which helps Google gauge how well its search algorithms are meeting user expectations.
Core Updates
During a core update, Google may adjust the algorithms’ logic, criteria, and the weighting of various signals. These updates can involve:
- Introducing new algorithms or retiring old ones.
- Changing how existing algorithms interpret signals from data sources like Navboost and IS scores.
- Adjusting the weights given to different ranking factors, which can change how heavily user interactions and evaluator feedback influence the final rankings.
Retraining of Ranking Systems
The new or modified algorithms are retrained on the latest datasets, which include the newly gathered data from Navboost and IS scores.
This retraining process allows the algorithms to “learn” from the most recent user behaviors and quality assessments.
This retraining is crucial because it helps the algorithms stay relevant and effective in a constantly changing internet landscape, reflecting the latest trends, user preferences, and content changes.
Re-evaluation and Ranking Adjustment
Once retrained, these ranking systems apply their updated models to re-evaluate websites across the internet.
This can lead to changes in how websites are ranked in search results. Websites might see their rankings change as a result of how well they align with the new ranking criteria.
You should also read Diagnosing and Solving Traffic Drops
Sites that better satisfy the updated criteria may rise in rank, while others may drop if they are less aligned with what the updated algorithms deem important.
Reduced clicks and engagement will feed back into systems like Navboost, which learns from user interactions to assess the relevance and usefulness of search results. This might lead Navboost to adjust its ranking of the page, potentially lowering its position in the SERPs.
When users do not click on a search result for a particular URL on SERP or demonstrate reduced it over time, it suggests several potential issues from an SEO perspective:
- Low Relevance of Title and Snippet: The title and snippet displayed in the search engine results page (SERP) may not effectively communicate the relevance or value of the content relative to the user’s query. This could indicate that the metadata is not well-optimized or engaging.
- Decreased Visibility and Attractiveness: The content might not seem appealing or relevant compared to other listings on the SERP, or it may not be providing the answers or information that users are expecting based on their search intent.
- Overall User Experience: A consistent lack of engagement can also reflect broader issues with the page or site, such as poor content quality, lack of updates, or diminished authority and trustworthiness.
As these user interaction metrics feed into Google’s broader ranking algorithms, a sustained negative dynamic of clicks could lead to a reassessment of the page’s quality or relevance, influencing its future visibility.
So, you should regularly monitor the performance of the page in terms of traffic, ranking, and engagement metrics.
If you see drop in clicks, ensure that the title and meta description accurately reflect the content on the page. Use engaging, actionable language that includes relevant keywords naturally.
What do you think about this?
Fact-checking
Dear readers, this article is based on the interpretation of the Pandu Nayak’s testimony and other documents in DOJ vs Google case.