You can freely build on Smart Ranking of Emails and Files Based on How You Click

What this patent covers

The system observes the order in which a user accesses a first set of objects, such as opening emails in an inbox, and compares this sequence to an 'access hypothesis'—a baseline expectation of how the user would normally browse them (Claim 1). If the user deviates from this baseline (for example, skipping the top three emails to click a receipt further down), the system adapts a 'preference model' (Claim 1). It does this by applying a 'bonus value' to the features of the early-accessed item (Claim 4) and a 'penalty value' to the skipped items (Claim 9). These updated weights, stored in feature vectors, are then used to calculate preferences and re-rank a second set of incoming items (Claim 1).

What is now free to use

All 0 claims of US 6370526 are in the public domain. Specifically:

The 0 dependent claims add narrowing limitations and are also free.

What is NOT covered

Patent expiry frees this specific invention. Separately-patented improvements made after expiry may still be protected.

• Does not cover ranking systems that rely purely on explicit user feedback, such as star ratings, likes, or manual folder sorting.

• Does not cover static ranking systems that do not update their underlying preference models dynamically based on user behavior.

• Does not cover systems where the baseline expectation (access hypothesis) is not compared against the actual sequence of user interactions.

• Does not cover ranking methods that do not use feature vectors to represent the attributes of the items being sorted.

Who is building on this today

IBM originally patented this for enterprise databases and email. Today, major email providers like Google and Microsoft, alongside search engine developers, use similar implicit feedback loops to train their ranking algorithms.

Products built on expired version of this technology

How to cite this patent in your documentation

International Business Machines Corp. US Patent 6370526. Self-adaptive method and system for providing a user-preferred ranking order of object sets. Granted 2002, expired 2019. Now in the public domain.

Note: This is a convenience citation. Consult a patent attorney for formal freedom-to-operate analysis.

PatentBrief is an educational resource and does not provide legal advice. Patent expiration information is derived from USPTO records and may not reflect continuation patents, divisional filings, or separately-patented improvements. For commercial use or production decisions, obtain a formal freedom-to-operate (FTO) opinion from a registered patent attorney.