Citing reference sources

When claim charting, it is important to provide details on where reference information can be found for quoted text, screenshots, and the like. While there are many different accepted formats for citing reference sources (e.g., Oxford, Harvard, MLA, IEEE, etc.), I do not specifically prefer one over another, and I don’t actually use any of these in my claim charts. What is key, at the most basic level, is to be sure to include sufficient details such that a reader can easily find the source information in the cited reference. And product information needs to be specific enough to help a client determine the amount of product exposure a patent read provides — that is, some versions of a product may use a patented claim while another version may not.

I find it rare to actually cite a book, magazine, or other printed reference nowadays — instead, in claim charts I usually include screenshots captured from one of a few types of references: websites, soft copies of user manuals (e.g., in PDF), and/or products. Because websites and user manual soft copies can  be referenced by a unique web address (aka Uniform Resource Locator, URL), I typically include only these URLs without also indicating an author or title. This is because normally the source information is gathered from a target vendor’s own website, which I find to be preferable to information from third party websites — you want to hear it straight from the target source, if you can. Normally claim charts are reviewed and used by a client in a fairly timely manner, so it is not typical that the URL would change or “break” in the interim, but in any case I recommend including a date of retrieval to indicate when the URL still included the information provided in the associated screenshot. A reader who tries to use the URL but does not see the information provided in the associated screenshot will quickly realize that something changed. In that case, it is often still possible to find the original information by using the Internet Archive’s “Wayback Machine”.

Regarding screenshots or photos of products, again it is imperative to include enough source information that fully delineates the product manufacturer, model, hardware version (if any), firmware version (if any), and software version (if any). Additional information may also be needed to adequately characterize the product — for example, an underlying operating system (including version) on which product software runs or a web browser in which a web application is run. Again, it is worthwhile to include a date of capture in case something later changes (e.g., web applications are often modified without a clear user-apparent version distinction). Consider this example: “Screenshot of the Doofenshmirtz Awesominator Web App running in Google Chrome browser on Windows 7 Professional SP1 operating system (captured June 24, 2013).”

Happy citing!

Patent Mining Search

An earlier post provides an overview of the various types of patent-related searches [Link], and another post summarizes some typical high-level steps taken in performance of a patent search [Link]. The following closely follows the overall search process described in the earlier post, but here concentration is on patent mining searches specifically.

A mining search is carried out in order to find and gather related patent assets — mining searches are usually performed for at least one selected technology area. This type of search is often executed on behalf of an entity which owns many patent assets and which may therefore not be fully aware of the scope of their portfolio. The patent assets uncovered in mining searches may then be rated, and these ratings can be leveraged to gather related assets for licensing or divestiture collections, and can also be used for maintenance decisions. Patent mining searching is an iterative process requiring continual refinement throughout searches, and it is often scoped to conclude with a set of a specific number of relevant patents which will then be reviewed in further detail. Sometimes the objective is to find all patents within a given technology area, but normally the objective is to find a specific number of patents within a given time limit. The scope of a mining search is not always limited to one owner’s portfolio, and for acquisition considerations, a mining search may include patents from a set of owners or even from any owner. Sometimes a limitation is put on searches to find only those patents with a specific amount of residual in-force lifetime.

Not all steps below necessarily need to be performed in the order listed, though this order has been shown to work well. Nor do all steps need to be performed at all – in practice, some search refinement often must be skipped due to time constraints. A patent analyst should continually consider the most productive path for gathering the strongest final set of patents based on what is discovered through search results along the way, and based upon given time constraints.

The set through which to search may need to be limited to one or more specific assignees or to one provided patent set.

1. Review technologies and target companies/products associated with the project. This step should definitely be performed first.
2. Formulate keywords and Boolean queries. Be prepared during searches to further refine the keyword set and Boolean queries.
3. Become familiar with patent search software functionality (if needed for the given software).
4. Perform searches using various keywords and Boolean query combinations. Perform first-pass searches using very targeted keywords and Boolean queries so as to find what may be the strongest matches up-front. Using these strong matches, you can leverage these patents to determine relevant patent classification codes and to perform semantic searches later. This step may be considered complete once all technology areas have been sufficiently searched.
5. Search using relevant USPTO/WIPO/EPO classifications (USPC, IPC, CPC). Relevant class codes can be manually determined through selected patents, and some patent search tools will indicate the most prevalent class codes in a patent set.
6. Search using the most relevant and prolific inventors found so far.
7. Search using cites/cited for patent references — reverse and forward citations, respectively.
8. Perform semantic searches using text from some of the best assets. Patent search software tools that provide semantic search functionality are recommended.
9. Know when to stop. This is probably the most difficult step, though budgetary constraints will often dictate this step. One good method to know when to stop is to see how the semantic searches pan out. If results from the semantic searches align well with earlier findings, then consider the search to be complete — if not, and the results appear to open another avenue, then continue refinement and searches until results become much less productive (i.e., the same assets keep showing up and new searches result in little or nothing new), within the budgeted time window.
10. Pre-filter the current asset set to eliminate patents that can quickly be dismissed and to get down to a specified number of results, if any.
11. Consider capturing family members of the most relevant references (siblings, parents, and children). You may wish to skip this step for now and only come back to it in a subsequent phase once most patents have already been filtered out. The reason being that patent families often fall together, and having too many assets in the same family might push out more relevant assets. The risk with not including family members is that a less relevant family member may be filtered out without providing the opportunity to review a well-aligned relative.
12. Collect and output the resulting set for next-stage analysis.


Bottom Line


Bottom line it.


My nature is to study details, and that’s one reason I enjoy patent analysis work so much. Being a detective is exciting, and it’s fun to delve deeply into a patent under review. There are numerous considerations to be made for a patent under review, and each subsequent phase of review entails analyzing additional aspects. Because of this, there is often a lot to say about how one reaches a conclusion and a recommendation for a given patent. Clients often provide a numeric rating system for assets so that they can more easily determine the best patents, filtering out those without as much potential. But even when they don’t use a rating system, clients appreciate a high-level summary of the conclusion and recommendation, and sometimes they do not wish to delve into the details as to why an analyst made the conclusion. So I recommend for verbal feedback to first provide a very short bottom-lined summary, and only go into the associated background details upon request. Additionally, for written communication, give the overarching bottom line up front (e.g., at the top of an email or on the far left of a table), and then subsequently provide supporting details.

Forward Citations as a Patent Relevance Metric

For a given patent (or patent application), a forward citation is another patent document’s citation back to that given earlier patent (from the perspective of the given patent). For a patent application, the associated patent applicant(s) and patent examiner(s) must disclose and cite existing references that may be material to the pending patent application, including patent document references. A citation can imply that the cited reference anticipates or renders obvious one or more claims of the pending application, or it may just denote that the cited reference discloses aspects related to a technology area associated with the pending application.

I have often heard from patent professionals that the number of forward citations that a given patent has is a strong indication of its relevance. In my experience, the number of forward citations metric often indicates something other than the relevance of associated claims within that patent document. First, one must consider that more-recently-issued patents will not have had much opportunity to be cited yet, which means that comparisons of forward citation metrics need to be limited to patents issued within a relatively narrow time frame. Second, with a duty to disclose, some patent applicants and practitioners cite many more references than might be needed or expected, and as such will include several patent references where the cited patent is not of particular relevance to the pending patent application. Next, in my experience, patent examiners will find “favorite” patent documents that have a large omnibus specification and describe well the state of the art at the time of application filing, but citations of these patent references indicate nothing about allowed/issued claims of these references. In fact, patent examiners do not normally specifically point to claims themselves, but to patent specifications and drawings, which means that there is no qualitative assessment of the claims themselves for a citation. Because the claims define the scope and value of an associated patent, and since the examiner is not referring to the claims in citations, one cannot read much of an indication of relevance into such a citation. Last, some large corporate patent filers have large collections of their own references in various technology areas to include in Information Disclosure Statements (IDS), thereby citing many of their own patent documents without specific regard to the actual relevance of these citations.

For these reasons, I always take the metric of the number of forward citations with a healthy pinch of skepticism — there is no substitute for actual claim analysis by an expert in the associated technology area. One numeric metric I find much more often indicative of relative patent quality (within a technology area and particularly within a patent family) is the number of words in independent claims — I’ll leave this discussion for another day.

For more information and perspectives, see:

I welcome your insights.

Google search tools for patent searching and analysis

When performing patent-related searches and/or analyses, I often leverage Google search tools to facilitate my work. A few examples are provided below, and I welcome others’ insight into other helpful search utilities. I should note that I sometimes also use Microsoft’s Bing search application, particularly because I earn Bing Rewards, but Google does have some specific patent-related utilities that Bing and other publicly-available and free search applications lack.

Google Images

When analyzing a patent and searching for either utilization or related art for inventive embodiments that include aspects that can be seen, such as mechanical designs or computer user interfaces, Google’s Images search results often are handy. A picture truly can be worth a thousand words, if not more. For example, I recently filed a patent application for an invention that my wife and I created for a unique drinking vessel. As part of my patentability assessment, I used Google Images to search for existing beer stein designs that might already disclose what we believed likely to be novel. So I searched using Google with the phrase “beer stein” (among many others of course), then I selected the “Images” link in the results — an example screen shot is shown below (from

Google Images
Google Images

Date Range

Additionally, when performing patent searches, normally there is a date range of interest. For example, for validity or patentability searches, a priority date is used to limit resulting references to those that precede the priority date of relevance. Google provides for date range selection in various different places, such as through selection of a “Search tools” button in a results banner. From there, a searcher may select a date or time range such as “Past hour”, “Past 24 hours”, “Past week”, etc. Normally the choice of interest is “Custom range…” (highlighted in the screen shot below from So for example, for a priority date of February 3, 2003, the “From” date field may be left blank, and “2/3/2003” may be entered for the “To” date field. This causes Google to only display results for references published before February 3, 2003.

Google Date/Time Range
Google Date/Time Range

Google Custom Date Range
Google Custom Date Range


When searching for potential patent claim utilization, clients often request specific target companies’ products. In those cases, the strongest references are those provided by a target company itself. Therefore, limiting search results to those provided by the target company is often helpful, and this can be done through use of a additional “site:” parameter. For example, to limit search results to those from “ACME Company, Inc.”, whose main domain is “”, enter normal search terms plus additionally include “”.

Advanced Search

Google also provides several other parameters that a searcher can use to limit results — these can be found in “Advanced Search” ( The Advanced Search can also be accessed through selection of the gear icon on a normal search results page. Results can be further limited, for example, through specifying explicit search term combinations, words to exclude, languages, etc. Screen shots are sourced from and

Google Settings
Google Settings
Google Advanced Search
Google Advanced Search

Prior Art Finder

And of course let’s not forget Google’s Prior Art Finder. For a given patent, Google will extract key terms and search for various types of references using those search terms where the references were published before the patent’s priority date. Additionally, a user can modify, remove, and add search terms and/or change the search’s date range. A key advantage of Google searches is that common synonyms for each search term are also used in the searches, and Google will sometimes leverage synonyms that a searcher may not have envisioned when creating a search plan. References can be sourced from scholarly references, other patent documents, books, the Web, people, or the top 10 from these groups. The example Prior Art Finder screen shot below is for US patent 6368227 for a method of swinging on a swing (

Google Prior Art Finder
Google Prior Art Finder