Smart Ranking of Emails and Files Based on How You Click
IBM's 1999 patent on automatically sorting lists of items, like emails, by watching which ones you click first and updating a mathematical model of your preferences in the background.
Original patent title: “Self-adaptive method and system for providing a user-preferred ranking order of object sets”
IBM's 1999 patent on automatically sorting lists of items, like emails, by watching which ones you click first and updating a mathematical model of your preferences in the background. Granted to International Business Machines Corp in 2002 with 38 claims and 135 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
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 (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 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).
The gap
What does this patent NOT cover?
- 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.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
Instead of just tracking what you click, the system compares your actions to an 'access hypothesis' (like assuming you will read top-to-bottom). By measuring how much you deviate from this baseline, it filters out the bias of screen layout.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Gmail's Priority Inbox sorting
Microsoft Outlook's Focused Inbox
Algorithmic sorting of search results in enterprise databases
Why it matters
The bigger picture
This patent represents an early foundation for algorithmic feeds and smart inboxes. Long before modern AI-driven social media feeds, IBM patented the core loop of implicit feedback: watching what a user ignores or clicks to silently re-order their view. It directly relates to features like Gmail's Priority Inbox or Outlook's Focused Inbox.
Filed
May 18, 1999
Granted
April 9, 2002
Market context
Who's building on this
Companies in this space
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.
Market impact
This patent helped establish the intellectual property landscape for implicit feedback loops. It moved the industry away from manual rules (like 'always put boss's email on top') toward dynamic, self-learning user interfaces that adapt without user intervention.
Claim 1 — Plain English
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).
The clever bit
Instead of just tracking what you click, the system compares your actions to an 'access hypothesis' (like assuming you will read top-to-bottom). By measuring how much you deviate from this baseline, it filters out the bias of screen layout.
What it does not cover
- 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.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Strong
Citation count
40/40
Highly cited
Claim breadth
20/20
Very broad protection
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$96K – $307K
Midpoint $192K · expired or expiring · industry ×1.6
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
38 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Seiffert, R., Srikant, R., Arning, A., & Agrawal, R. (2002). Smart Ranking of Emails and Files Based on How You Click (U.S. Patent No. 6,370,526). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/6370526/google-adwords-pay-per-click
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does Smart Ranking of Emails and Files Based on How You Click cover?
IBM's 1999 patent on automatically sorting lists of items, like emails, by watching which ones you click first and updating a mathematical model of your preferences in the background.
Who owns patent US 6370526?
International Business Machines Corp owns this patent, granted in 2002.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 6370526 cited by?
This patent has been cited by 135 later patents that build on its ideas.
What problem does this patent solve?
This patent represents an early foundation for algorithmic feeds and smart inboxes. Long before modern AI-driven social media feeds, IBM patented the core loop of implicit feedback: watching what a user ignores or clicks to silently re-order their view. It directly relates to features like Gmail's Priority Inbox or Outlook's Focused Inbox.
What does this patent NOT cover?
Does not cover ranking systems that rely purely on explicit user feedback, such as star ratings, likes, or manual folder sorting.
Same assignee
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