What does Google say about SEO? /

Official statement

To determine the weight of a ranking signal, Google uses data from experiments and human evaluators (raters) that reflect how users interact with search results. These metrics help decide whether or not to launch a change.
🎥 Source video

Extracted from a Google Search Central video

💬 EN 📅 06/05/2021 ✂ 26 statements
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Other statements from this video 25
  1. Is loading speed really just a secondary ranking factor?
  2. How does Google adapt the weight of its ranking signals after their launch?
  3. Can a site's speed make up for mediocre content?
  4. Is measuring only the LCP a strategic mistake for your SEO?
  5. How does Google truly validate its ranking signals before rolling them out?
  6. Does Google really differentiate between two types of ranking changes?
  7. Why does your Google ranking fluctuate so much based on the location of the query?
  8. Why does Google crawl your site at a different speed than what your users experience?
  9. Is it true that Google refuses to disclose the exact weights of its ranking factors?
  10. Why does Google really prioritize speed as a ranking factor?
  11. Why doesn’t Google care about speed spam?
  12. Why can SEO metrics indicate regression while user experience improves?
  13. Should we still focus so much on loading speed?
  14. Is HTTPS just a simple tiebreaker between equivalent sites?
  15. Is it true that HTTPS is merely a 'tie-breaker' in Google rankings?
  16. Why does Google sometimes measure the impact of an update with negative metrics?
  17. Is loading speed really just a minor ranking signal?
  18. Is site speed really secondary to content relevance?
  19. Why is measuring only LCP no longer enough for Core Web Vitals?
  20. Why does Google differentiate between crawl speed and user speed?
  21. Why do your search results vary by region and language?
  22. Is your site truly global or just multilingual?
  23. Should you really invest in speed optimization to combat spam?
  24. Why does Google refuse to reveal the exact weight of its ranking factors?
  25. Why does Google prioritize speed as a ranking factor?
📅
Official statement from (4 years ago)
TL;DR

Google relies on controlled experiments and human evaluators to calibrate the weight of each ranking signal. This data helps predict how real users will interact with the results. For SEO, this means that no signal holds absolute value—everything depends on its measured impact on user satisfaction in a given context.

What you need to understand

What does Google mean by "experiments" and "evaluators"?<\/h3>

Experiments<\/strong> are large-scale A/B tests conducted by Google on a fraction of traffic. The Quality team launches two versions of the algorithm in parallel: one with the tested signal (for example, a new weight for content freshness), the other without. Satisfaction metrics—reading time, clicks, query reformulations—are compared to determine which performs better.<\/p>

Human evaluators<\/strong> (raters) are contractors trained through the Search Quality Rater Guidelines<\/strong>. They rate the relevance of results according to strict criteria: E-E-A-T, content quality, query intent. These ratings do not directly modify rankings but serve as a barometer to validate or reject an algorithmic change.<\/p>

Why does this approach change the game for an SEO practitioner?<\/h3>

This means that a performance signal on paper can be rejected<\/strong> if real users do not derive measurable benefit from it. A concrete example: Google tested the weight of Core Web Vitals<\/strong> in 2021 before rolling them out. Teams found that the impact on satisfaction was real but less massive than expected—hence a moderate weight in the overall ranking.<\/p>

For us, this means that optimizing an isolated signal (for example, stuffing a site with keywords) makes no sense if the overall user experience does not follow. Google is not seeking technical perfection—it looks for results that users prefer to consume<\/strong>.<\/p>

How does Google decide the "right" weight for a signal?<\/h3>

The process is iterative. Once the experiment is launched, Google cross-references three types of data<\/strong>: behavioral metrics (CTR, pogosticking, time on page), evaluator scores, and secondary signals (number of reformulations, clicks on competing results). If the three converge, the signal is validated. If a discrepancy arises, the team adjusts or abandons.<\/p>

What matters is the correlation between the signal and satisfaction<\/strong>. A signal can be technically brilliant—for example, advanced semantic analysis—but if users do not click more on the results that benefit from it, it will be underweighted or even ignored. Google does not engage in science for science's sake.<\/p>

  • A/B experiments measure the real impact of a signal on user behavior<\/strong><\/li>
  • Human evaluators validate that the results meet the qualitative expectations defined in the Guidelines<\/strong><\/li>
  • No signal has a fixed weight—everything depends on the query context and user intent<\/strong><\/li>
  • A signal may be technically valid but ignored if its impact on satisfaction is marginal<\/strong><\/li><\/ul>

SEO Expert opinion

Is this statement consistent with observed practices on the ground?<\/h3>

Yes, and it’s even one of the few statements that explains why some signals don’t work<\/strong> as we think. Take the case of loading time<\/strong>: we know Google values it, but not in a linear fashion. A site going from 3 to 2 seconds does not necessarily gain visibility. Why? Because experiments have likely shown that the impact on satisfaction concentrates on critical thresholds<\/strong> (going from 6 to 3 seconds, for example), not on micro-optimizations.<\/p>

Another example from the field: algorithm updates like the Helpful Content Update<\/strong>. Google tested for months before deploying, cross-referencing evaluators and live metrics. The result? Some technically flawless sites lost traffic because evaluators rated them poorly on originality and depth<\/strong>. Experiments validated this correlation—and Google launched.<\/p>

What nuances should be added to this assertion?<\/h3>

The problem is that Google never specifies which signals are tested or with what final weight<\/strong>. We know experiments exist, but we do not know the exact metrics or validation thresholds. [To verify]<\/strong>: does Google test ALL signals in this way, or only new ones? Nothing explicitly confirms it.<\/p>

Another gray area: the evaluators do not cover all languages or markets<\/strong> with the same intensity. A signal validated on English queries may behave differently in French or Japanese. Google seldom admits this, but geographical variations in SEO performance are indirect proof.<\/p>

In what cases does this rule not apply or become counterproductive?<\/h3>

Google does not test in real-time every individual query. If you work in a super-specialized niche<\/strong> (e.g., SEO for an obscure B2B software), the behavioral metrics are too low to support a meaningful experiment. Google then relies on generic heuristics<\/strong>—which explains why some niche sectors respond poorly to "best practices".<\/p>

Another limitation: Your Money Your Life (YMYL) queries<\/strong>. Here, Google overemphasizes the evaluators’ opinions at the expense of behavioral metrics. Why? Because medical content can be popular (clicks, time spent) while being harmful. The algorithm does not trust users alone—it imposes a stricter human editorial filter<\/strong>.<\/p>

Attention:<\/strong> If you optimize solely for behavioral metrics (CTR, dwell time), you risk missing out on the qualitative criteria<\/strong> that evaluators scrutinize. A balance between technical performance and editorial depth remains essential.<\/div>

Practical impact and recommendations

What concrete steps should be taken to align your SEO with this logic?<\/h3>

Start by analyzing the behavioral metrics of your pages<\/strong>: CTR in SERPs, bounce rate, average time on page, pages per session. If a page performs technically (speed, mobile-friendly) but has a low CTR or high pogosticking, it means that the content does not meet the intent<\/strong>. Google will detect this and adjust rankings—regardless of your PageSpeed score.<\/p>

Next, read and apply the Search Quality Rater Guidelines<\/strong>. This is the framework that Google uses to train its evaluators. If your content fails to meet the E-E-A-T criteria (expertise, experience, authority, trust), experiments will reveal a gap between technical signals and satisfaction—and you will lose ground. Specifically: add identifiable authors, verifiable sources, and evidence of genuine expertise.<\/p>

What mistakes should be avoided to not skew your own SEO "experiments"?<\/h3>

Never test a single isolated signal expecting a magic gain. Google cross-references dozens of signals—if you optimize speed but your content remains hollow, the overall user experience does not improve<\/strong>. Internal A/B tests should measure the impact on composite metrics (engagement + conversion + satisfaction), not on a single technical KPI.<\/p>

Another pitfall: ignoring qualitative feedback. Analytics tools provide numbers, but they do not tell you why<\/strong> a user leaves a page. Complement this with user testing, Hotjar sessions, and post-visit surveys. This is what Google evaluators do—and you need to do the same to anticipate their verdicts.<\/p>

How can you verify that your site is aligned with Google's criteria?<\/h3>

Conduct a rigorous E-E-A-T audit<\/strong>: who signs your content? Do you have credible bios, mentions in reputable media, editorial backlinks? If a human evaluator lands on your site, can they verify your legitimacy in under 30 seconds? If not, fix it.<\/p>

Then, compare your behavioral metrics to those of your direct competitors. If your organic CTR is consistently below the average for your position, it means your title and meta description are not compelling enough<\/strong>—or that your brand lacks visibility. Google captures these signals and adjusts rankings accordingly.<\/p>

  • Analyze CTR, bounce rate, time on page, and pogosticking for each strategic page<\/li>
  • Audit your content according to the E-E-A-T criteria from the Search Quality Rater Guidelines<\/li>
  • Add identifiable authors, verifiable sources, and evidence of expertise<\/li>
  • Test the overall user experience, not isolated signals<\/li>
  • Compare your behavioral metrics to those of your direct competitors in SERPs<\/li>
  • Complement analytics with qualitative user testing (Hotjar, surveys)<\/li><\/ul>
    Modern SEO optimization is no longer just about checking technical boxes. Google measures the real impact of each signal on user satisfaction—and rejects those that don’t provide tangible value. To align your strategy, cross-reference behavioral data, E-E-A-T qualitative criteria, and user feedback. This holistic approach requires in-depth expertise and continuous monitoring. If the complexity of these cross-optimizations seems difficult to manage alone, partnering with a specialized SEO agency can help you structure a coherent and measurable strategy.<\/div>

❓ Frequently Asked Questions

Les évaluateurs humains de Google modifient-ils directement le classement de mon site ?
Non. Les évaluateurs notent la qualité des résultats pour valider ou rejeter des évolutions algorithmiques, mais leurs notes ne changent pas directement le classement d'une URL. Leur rôle est de fournir un référentiel qualitatif que l'algorithme apprend à reproduire.
Comment Google mesure-t-il concrètement la satisfaction utilisateur dans ses expériences ?
Google croise plusieurs métriques : CTR, temps passé sur la page, taux de reformulation de requête, clics sur des résultats concurrents, et signaux de navigation (retour rapide à la SERP, profondeur de navigation). Ces données sont comparées entre groupes de test et groupes témoins.
Un signal SEO peut-il avoir un poids différent selon le type de requête ?
Oui, absolument. Google adapte le poids des signaux en fonction de l'intention de recherche. Par exemple, la fraîcheur du contenu pèse plus lourd pour une requête d'actualité que pour une requête informationnelle générique. C'est le résultat d'expériences spécifiques par type de requête.
Les Search Quality Rater Guidelines sont-elles un blueprint exact de l'algorithme ?
Non, mais elles reflètent les critères que Google cherche à reproduire algorithmiquement. Les Guidelines servent à former les évaluateurs — et les notes de ces évaluateurs valident si l'algorithme produit des résultats conformes à ces critères. C'est un proxy, pas une réplique exacte.
Si mes métriques comportementales sont bonnes mais que je perds du trafic, que se passe-t-il ?
Ça peut signifier que les évaluateurs humains notent mal votre contenu sur des critères qualitatifs (E-E-A-T, profondeur, originalité) que les métriques comportementales ne captent pas. Google croise les deux sources — si elles divergent, l'avis des évaluateurs peut l'emporter, surtout en YMYL.

🎥 From the same video 25

Other SEO insights extracted from this same Google Search Central video · published on 06/05/2021

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