How does Google really use signals and ranking factors in its systems?

Danny Sullivan used a simple yet enlightening metaphor to explain the distinction between the concepts of signals, factors, and ranking systems in Google. According to him, signals and factors are like fuel, while systems represent the machine that uses this fuel.

This clarification is important because it highlights that signals and factors refer to exactly the same thing. They are raw data that Google collects: loading speed, backlinks, content freshness, behavioral signals, etc.

The ranking systems are the algorithms that process these signals. The same signal can be used by several different systems, and each system can weight signals differently depending on the query context.

• Signals/Factors: raw data collected (links, content, speed, etc.)
• Systems: algorithms that interpret and weight these signals
• The same signal can have different weight depending on the activated system
• Systems are activated according to context and search intent

This metaphor from Danny Sullivan is perfectly consistent with what we have been observing in the field for years. It notably explains why the same site can rank well for certain queries and less well for others: the activated systems are not the same.

However, this approach needs to be nuanced. In practice, the boundary between signal and system is sometimes blurred. For example, the Helpful Content system itself generates a quality signal that can be used by other systems. We are therefore witnessing a form of nesting where the outputs of certain systems become the inputs of others.

The real complexity lies in the fact that Google never reveals how each system weights the signals. We must therefore continue to work on overall excellence rather than attempting to optimize for a specific system. This holistic approach remains the most sustainable strategy.

This clarification from Google invites us to rethink our strategic approach to SEO. Rather than targeting isolated "factors," we must understand that our optimizations fuel multiple interconnected systems.

• Adopt a systemic vision: optimize for multiple systems simultaneously rather than for isolated factors
• Diversify your positive signals: don't put all your eggs in one basket of optimization (technical, content, links)
• Analyze fluctuations according to query types: this reveals which systems are activated for your topics
• Stop searching for the miracle factor: no single signal guarantees ranking, it's the whole that matters
• Document your observations: note which types of signals seem favored for your target queries
• Maintain overall excellence: work simultaneously on technical aspects, content, authority, and user experience