20-21 April 2015, Nice
EXPLORING CITATIONS: BENEFITS AND CHALLENGES
• Why this topic?
• Citations are often underused and underestimated by
• This is often due to misunderstandings and the inherent
complexity of patent citation data
• Difficulty to grasp the full picture of patents being cited
• Difficulty to explore and navigate properly citation data
• However, despite many challenges, there are
many benefits to the use of patent citations
• Citations: the basics
• Citations: the source(s)
• Citations: why and what for?
• Citations: explore, investigate, analyse
1. Patent citations
What is a patent citation?
• A document “cited” because its content
is related to a current patent application
Who assigns citations?
• An applicant - knows, or is made aware, of
related prior art and cites it
• A patent office examiner – finds additional related documents during
searches while checking the patentability of a patent application
What can be cited?
• Anything that is publically available:
• An existing patent publication
• Scientific literature, such as a journal article
• Internet publications
• Conference proceedings, Academic publications…
Citation coverage, search options and visualisation tools vary
BUT searchable patent resources always allow:
• Searching and identifying both forward (citing) and backward
A forward citation
A newer document (CITING the – or one of the - patent
application(s) under consideration). Therefore, a more RECENTLY
A backward citation
An earlier published document (CITED by the – or one of the -
patent application(s) under consideration). Therefore, an OLDER
The Common Citation Document (CCD)
The CCD is a free citation search resource recently developed by
the Trilateral Offices (EPO, USPTO and JPO + CN and KR) to
provide single point access to these three collections of citation
2. Citation sources
Where does citation data come from?
• Some national patent offices provide it
BUT the largest source of raw citation
data is REFI - Reference File Citation Database
What is REFI?
• Citation data collected by
The European Patent Office
from patent offices
around the world.
• Previously an independent file,
it is now incorporated into
the EPO’s data feeds.
REFI is a growing data set
Additions to REFI by The EPO in 2014*
• > 20 million cited references added to the database:
• 4 million for Japan
• 2 million for China
• 9.7 million for US grant (B1,B2)
• 3 million for US pre-grant (A1)
Latest REFI updates can be found at:
*Data courtesy of Florent Lina, EPO XML Raw Data Day presentation , 18 March 2015
PatBase uses REFI as the backbone to its citation collection supplementing
that with national office collections, for example those from the USPTO
and the German Patent Office (DPMA)
We take multiple data sets to combat issues with collections such as:
• consistency in number formatting
• gaps or delays in data supplied
Citation relevancy indicators and citation origins bring their own problems:
• Provision / consistency / only covers patents examined by EPO
At Minesoft, with the help of our partner RWS, we have initiated a complex
task to re-index all citation data to provide better citation data
• Almost all countries provide at least the citations from
the search reports
• BUT citations can be extracted from:
• Applicant filings (IDS, fulltext…)
• 3rd Party Observations
• Examination (other than Public Search Report)
• Opponent filings (during oppositions or Appeals)
• Even though the data may exist many countries do not
provide these other citations
Data holdings list of REFI
Inconsistency with provision of citation origins across countries
3. Why use citation searches?
• To benefit from the patent
examiner experience and prior
• To discover other closely
related patents and literature
• To expand or enhance a keyword
search (particularly when the
technology field is new and you
are not certain of the terms or the
Why use citation searches?
• To analyse your own patent portfolio:
Determine your most “important” patents
- what patents are most cited and by whom?
- which of your technologies are most frequently cited?
- is there new actors citing your patents?
If it is relatively easy to extract and
review patent citations at a given point in time,
it is however a complex task to identify
the new patent citations
Why use citation searches?
• For Competitor intelligence and business information
To monitor who is citing your patents:
• Identify new citings of your patent(s)
• Discover new competitors entering your field of technology
• Find potential licensing opportunities
• Help identify white space within technologies
Minesoft’s new CiteTracker can assist you to do this.
How does CiteTracker work?
CiteTracker monitors citation activity, providing alert reports to inform clients of
any new patent citation, allowing to immediately identify:
- Who is citing their company’s / client’s patents?
- Which new competitors are entering their space?
- What licensing opportunities are emerging?
- Who is citing a particular technology?
Alerts run weekly, notification is emailed and incorporates a direct
access to the online report with the necessary tools to immediately
identify the citations (remove self-citations, easy filters, exports…)
4. Analysing citation data
• Use an intuitive platform
• Access statistics / graphs
• Use visual aids such as trees and timelines
• Use filtering; for example, to select one
assignee you are interested in
• Compare claims, descriptions and
images (side by side)
• Track citation pathways
• Save or flag documents of interest
• Make notes to share with colleagues
PatBase new Citation Module aims being a
single tool for reviewing, exploring and
investigating citation data
Benefits of citation searches
Citation searches are not only an excellent complement to other patent
searches, they are very useful in their own right.
• Find relevant patents not found during an initial
patent classification or keyword search
• Trust in, and exploit, the expertise of the patent
examiners (they have identified documents
• Gain new, and/or different, terminology to improve
your searches and your understanding of technological sectors
• Identify licensing opportunities
• Evaluate the status of a patent
Citations – potential pitfalls
• Quality of data, i.e. consistency of number formatting
• Coverage of data set searched
• Number of citations:
• The number of citations (sometimes over a hundred) applied to one
document => some platforms limit the number of available citations to 99
• Some patents receive no citations
• Difference of systems throughout the patent world
• Difference of interpretation by individuals
• Tenuous links to relationships between technologies
• Recent patents have far less forward citations than older patents -
when carrying out analysis time lags should be taken into account
Getting the most
out of citations
Citations are a valuable resource not
only for capturing documents but for
analysing and valuing patent portfolios
• Exploit the benefits
• Take into account potential pitfalls
• Find efficient resources to assist you in your searches
• Make use of available tools to aid interpretation and analysis
Thank you for your attention
Olivier Huc - email@example.com
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Special thanks to my colleagues Sophie Halliwell & Ian Perriman