multiple CPC_class_symbol code for the same application id

Here you can post your opinions, ask questions and share experiences on the PATSTAT product line. Please always indicate the PATSTAT edition (e.g. 2015 Autumn Edition) and the database (e.g. PATSTAT Online, MySQL, MS SQL Server, ...) you are using.
Post Reply

dvencappa
Posts: 4
Joined: Tue Mar 30, 2021 6:20 am

multiple CPC_class_symbol code for the same application id

Post by dvencappa » Tue Mar 30, 2021 6:37 am

Hi EPO experts,
I am interested in counting the number of patents granted by specific CPC codes (CPC_class_symbol) for each patent application/patent granted for firms in the UK. When I query the data (I combined tables
tls201, tls202, tls207, tls224, tls906 to get this), I note that in many instances, for the same appln_id (or docdb_family_id or any other id used for a patent), this returns multiple CPC codes (this is usually a mix of more general CPC codes as well as more detailed CPC codes). I am somewhat confused here and was under the impression that each patent applied on a specific filing date would have a single CPC_class_symbol. Can you please clarify which unique patent ID I should be using to ensure there is no double counting of the various CPC codes? For example, if a firm has applied for one patent but this has 4 CPC codes assigned to it, should I say the firm applied for one patent or 4 patents?

Any insights on this would be useful.


Regards,
Dev


EPO / PATSTAT Support
Posts: 244
Joined: Thu Feb 22, 2007 5:33 pm
Contact:

Re: multiple CPC_class_symbol code for the same application id

Post by EPO / PATSTAT Support » Tue Mar 30, 2021 1:14 pm

Hello Dev,
patent applications will normally always have more then 1 patent classification code, be it CPC, IPC or F-FI. That is exactly the purpose of the classification codes, to represent different technical aspects of the invention.
If you want to dive (very) deep into the "how and what" on classification codes have a look at this IPC manual - which principles are equally applicable to CPC.
wipo_guide_ipc_2020.pdf
(320.07 KiB) Downloaded 6 times
To answer your questions:
a single patent application is still 1 single patent application; independent from the number of assigned classification symbols.
Researchers sometimes "prune" the codes to 8 or even 4 digits if the full level of granularity is not needed for the purpose of their research.
If you do need the full level of granularity, then you could apply weighing so that each assigned classification code gets "a share of the patent". As a result, the "sum of the shares" will be equal to the total number of patents --> no double counting.

A small word of warning: whatever approach you use is dependant on your research question and one has to be care full not to make wrong conclusions on simply "counting patents as a proxy for innovative capacity".

Hypothetical example: take 2 companies A/B that have each filed 1 patent.
Patent A has 1 classification symbol: Y02E10/70 for "wind energy" --> weighted value = 1
Patent B has 3 classification symbols: Y02E10/70 (wind energy), F05B2250/25 (3-dim/helical) and F05B2240/243 (of the Archimedes screw type) --> weighted value 1/3 for each symbol.
Conclusion when comparing A versus B on wind energy: Company A is 3 times more innovative (value 1) versus company B (1/3) in the field of wind energy... this is of course nonsense. Both companies have each 1 patent in the field of "wind energy". Company B might in fact be more innovative as it combines different technologies in 1 patent.
PATSTAT Support Team
EPO - Vienna
patstat @ epo.org


dvencappa
Posts: 4
Joined: Tue Mar 30, 2021 6:20 am

Re: multiple CPC_class_symbol code for the same application id

Post by dvencappa » Wed Apr 14, 2021 5:43 am

Hello thank you for this clarification - this is very much appreciated. I have another question which I will be posting in a separate post.


Post Reply