DCT
4:17-cv-04709
LookSmart Group Inc v. Microsoft Corp
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Looksmart Group, Inc. (Nevada)
- Defendant: Microsoft Corporation (Washington)
- Plaintiff’s Counsel: Hosie Rice LLP
- Case Identification: 4:17-cv-04709, N.D. Cal., 08/15/2017
- Venue Allegations: Venue is alleged based on Microsoft's regular and established places of business within the Northern District of California, including a data center in Santa Clara, where acts of infringement are alleged to occur.
- Core Dispute: Plaintiff alleges that Defendant’s Microsoft Bing search engine infringes a patent related to methods for ranking the relevancy of web pages.
- Technical Context: The lawsuit concerns foundational web search engine technology, specifically algorithms that determine the order of search results by analyzing page content and the structure of links between pages.
- Key Procedural History: The complaint alleges that Microsoft has had knowledge of the patent-in-suit since at least July 2008. It details numerous instances where the patent was cited by the U.S. Patent and Trademark Office during the prosecution of Microsoft's own patent applications, as well as instances where Microsoft itself submitted the patent in Information Disclosure Statements and provided detailed analysis to distinguish its own inventions from the patent-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 2001-01-10 | '530 Patent Priority Date |
| 2008-04-08 | '530 Patent Issue Date |
| 2008-07-24 | Earliest alleged date of Microsoft's knowledge of the '530 Patent |
| 2017-08-15 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,356,530 - "Systems and Methods of Retrieving Relevant Information" (issued April 8, 2008)
The Invention Explained
- Problem Addressed: The patent addresses the challenge of finding relevant information on the World Wide Web, which, due to its rapid growth and "lack of central organization," often yields an overwhelming number of search results for any given query. ('530 Patent, col. 1:12-19). Furthermore, ranking methods based solely on a page’s content are susceptible to manipulation or "spamming," where an author repeats keywords to artificially inflate a page's relevance. ('530 Patent, col. 3:20-26).
- The Patented Solution: The invention discloses a method for ranking pages by combining two distinct types of analysis: an "intrinsic rank" and an "extrinsic rank." ('530 Patent, Abstract). The intrinsic rank measures a page's relevance based on its own content (e.g., keywords in the title or text), which is then adjusted by a "page weight"—a measure of the page's overall importance. ('530 Patent, col. 6:42-54). The extrinsic rank provides a more objective measure by analyzing the "link structure" of the web, considering the anchor text of inbound links and the page weight of the linking pages. ('530 Patent, col. 8:51-65). Figure 1 of the patent illustrates a system architecture with components such as a crawler, indexer, and ranker designed to implement these methods. ('530 Patent, Fig. 1).
- Technical Importance: The combination of on-page content analysis with off-page link-based analysis represented a significant step in improving the quality of web search results beyond simple keyword matching. (Compl. ¶¶ 23, 25).
Key Claims at a Glance
- The complaint asserts independent claims 1 and 10, as well as dependent claims 6 and 12, but provides a detailed infringement analysis only for claim 10. (Compl. ¶ 29).
- The essential elements of independent claim 10 include:
- crawling the Web to produce a collection of pages without limitation to topic;
- selecting words from the pages without a priori knowledge of keywords in a query;
- ranking the pages for the selected words;
- determining an intrinsic ranking factor by examining page content to determine a content score and adjusting that score by the page weight;
- determining an extrinsic ranking factor by examining text (anchor weight) associated with inbound links from linking pages and adjusting that anchor weight by the page weight of the linking page;
- ranking each page by combining the intrinsic and extrinsic ranking factors; and
- creating a searchable data structure of the ranked pages.
III. The Accused Instrumentality
Product Identification
The accused instrumentalities are the "Microsoft Bing technology and services" as provided through websites such as bing.com and msn.com. (Compl. ¶ 29).
Functionality and Market Context
The complaint alleges that the Bing search engine operates by using "Bingbots" to crawl the web and build an index of pages. (Compl. ¶ 31). It is alleged to use a system named "Maguro" to compute ranking scores for pages based on both "intrinsic" factors, such as a website's content and keyword placement, and "extrinsic" factors, such as the quality and text of incoming links. (Compl. ¶¶ 33-34, 36). The complaint references Microsoft's own webmaster blogs and a research paper to describe these functions, alleging that Bing combines these factors to determine the final rank of search results. (Compl. ¶¶ 34, 36, 37).
IV. Analysis of Infringement Allegations
The complaint reproduces Figure 1 from the patent, which depicts a search engine architecture, to help illustrate the patented methods. (Compl. p. 7, Fig. 1). This figure shows the interrelation of components like the crawler (12), indexer (26), and ranker (30) that are central to the infringement allegations.
'530 Patent Infringement Allegations
| Claim Element (from Independent Claim 10) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| crawling the Web to produce a collection of pages without limitation to topic; | Microsoft Bing uses "Bingbots" to automatically crawl the World Wide Web to build an index of new and updated pages, collecting information from websites without limiting the topics. | ¶31 | col. 15:9-10 |
| selecting words from the pages of the collection of pages without a priori knowledge of keywords in a query; | Bing allegedly collects text from crawled pages to build its indexes in order to match future search terms, without a priori knowledge of what those search queries will be. | ¶32 | col. 15:11-13 |
| ranking the pages in the collection of pages for the selected words by, for each of the selected words with regard to each of the selected pages; | Bing allegedly ranks the pages it collects using a system called "Maguro" which computes ranking scores for pages for each selected word (or "atom"). | ¶33 | col. 15:14-17 |
| determining an intrinsic ranking factor by examining content related to the selected word on the selected page to determine a content score and adjusting the content score in accordance with the page weight of the selected page; | Bing is alleged to rank pages based on intrinsic factors, including the page's content and "selective placement of certain words," and also considers "page weight factors" to determine a page's quality and importance, which "impact[] the ranking." | ¶34 | col. 15:18-23 |
| determining an extrinsic ranking factor for use of the selected word on the selected page by, for each linking page... examining text associated with the outbound hypertext link... to determine an anchor weight for the linking page, adjusting the anchor weight in accordance with the page weight of the linking page and combining the adjusted anchor weights... | Bing allegedly considers extrinsic factors, such as incoming links, and examines the associated anchor text to help define the theme of a linked page. It also allegedly adjusts this value based on the importance ("page weight") of the linking page. | ¶36 | col. 15:24-36 |
| ranking each selected page for each selected word by combining the intrinsic and extrinsic ranking factors related thereto; and | Bing allegedly combines the various intrinsic and extrinsic ranking factors it considers to rank a page for a given keyword. | ¶37 | col. 15:37-40 |
| creating a searchable data structure related to the pages in the collection of pages indexed in accordance with the selected words... so that search results... are already ranked... | Bing is alleged to create its own searchable data structures (hash-based indexes) where pages are indexed with "atoms" (words), and a "pre-computed ranking score" is used to provide ranked search results. | ¶38 | col. 15:41-48 |
- Identified Points of Contention:
- Scope Questions: A central dispute may arise over the term "page weight." The patent defines this term as a specific probability of a user visiting a page based on a random walk model. The question is whether the complaint's allegation that Bing uses "page weight factors" to assess "quality and importance" meets the more specific, mathematical definition required by the patent. (Compl. ¶34; ’530 Patent, col. 7:13-15).
- Technical Questions: The complaint alleges Bing uses a system called "Maguro" to generate a "pre-computed ranking score." (Compl. ¶¶ 33, 38). A technical question for the court will be whether the operation of this system embodies the distinct steps of determining separate intrinsic and extrinsic factors and then "combining" them, as laid out in claim 10, or whether it employs a different, more integrated algorithmic approach that does not map to the claim's structure.
V. Key Claim Terms for Construction
The Term: "page weight"
- Context and Importance: This term is a critical component of both the "intrinsic" and "extrinsic" ranking steps of claim 10. The case may turn on whether the "page weight factors" allegedly used by Bing to assess page "quality and importance" can be proven to be the same as the "page weight" described in the patent. (Compl. ¶34).
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification states that "Since the page weight is the probability for a user to visit a page, it can also represent the importance of each page." ('530 Patent, col. 8:15-16). This language may be used to argue that any metric representing page "importance" falls within the term's scope.
- Evidence for a Narrower Interpretation: The patent provides a specific technical definition: "Page weight of a page is defined as the probability for a user—who travels on the Web endlessly in a random but well-defined manner—to visit the page." ('530 Patent, col. 7:13-15). This suggests a specific, mathematically derived value, not just a general assessment of quality.
The Term: "combining the intrinsic and extrinsic ranking factors"
- Context and Importance: This is the culminating step of the claimed ranking method. Practitioners may focus on this term because the dispute will likely involve whether Bing's complex, multi-signal algorithm performs the specific "combining" action recited in the claim.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim language itself does not specify a particular method of combination, which may support an argument that any algorithm that considers both types of factors to produce a final rank meets this limitation.
- Evidence for a Narrower Interpretation: The detailed description provides a specific formula for combination:
WR(K;a)=IR(K;a)+e·ER(K;a), an additive combination of the two factors. ('530 Patent, col. 6:39-40). This may support a narrower construction limited to this type of explicit mathematical combination.
VI. Other Allegations
- Indirect Infringement: The complaint does not plead a separate count for indirect infringement.
- Willful Infringement: The complaint makes extensive allegations supporting willfulness. It claims Microsoft had pre-suit knowledge of the '530 patent since at least July 24, 2008. (Compl. ¶39). This allegation is supported by references to the prosecution histories of at least fifteen different Microsoft patents where the '530 patent was cited as prior art. (Compl. ¶39). The complaint specifically notes instances where Microsoft itself submitted the '530 patent in Information Disclosure Statements and where it argued to distinguish its own pending claims from the '530 patent’s teachings, suggesting a detailed, pre-suit analysis of the patent by Microsoft's inventors and counsel. (Compl. ¶¶ 40-43).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can the term "page weight", which the patent defines with specific, probabilistic language related to a "random walk" model, be construed to cover the more general "page weight factors" and "quality" signals that Bing allegedly uses to rank pages?
- A key evidentiary question will be one of technical mapping: does the evidence concerning the internal workings of Bing's "Maguro" ranking system show that it performs the distinct claim steps of calculating separate intrinsic and extrinsic factors and then "combining" them, or does it operate as a holistic algorithm whose functions cannot be cleanly mapped onto the structure of Claim 10?
- A central issue for damages will be willfulness: given the complaint's detailed allegations that Microsoft and its counsel repeatedly analyzed the '530 patent during the prosecution of their own patents years before the lawsuit, the court will have to determine whether Microsoft's continued use of its Bing technology constituted objective recklessness with regard to Looksmart's patent rights.