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forward citation (Families)

Posted: Thu Nov 15, 2018 4:50 pm
by Pasdeprenom
Dear Geert,

I am interested in counting forward citations of families (Number of families citing a family).
I have found different references about it and specially about the date that I have to choose to make the time window. (publn_date, earliest_filing_year,grant_date, etc).
If I use the priority year for both families, I find a negative lag in several cases.

Thank you in advance,

Manuel Jimenez

Re: forward citation (Families)

Posted: Mon Nov 19, 2018 9:48 am
by EPO / PATSTAT Support
Hello Manual,
can you give some examples or share your code ?
And why it would be a problem.

Re: forward citation (Families)

Posted: Mon Nov 19, 2018 11:27 am
by Pasdeprenom
Yes, I am sorry. My problem is that I don’t know what date is more recommended for citation windows. I have found a paper (De Rassenfosse, G., Dernis, H., & Boedt, G. (2014). An introduction to the Patstat database with example queries. Australian Economic Review, 47(3), 395-408.) where the publn_date is used to make it.
Is this the best way? For forward citation by family, Should I do a “group by” after?


Thank you so much

kind regards.

Manuel

Re: forward citation (Families)

Posted: Mon Nov 19, 2018 12:18 pm
by EPO / PATSTAT Support
Hello Manual,
the purpose of the limitation on a time frame for forward citations is to avoid bias. In simple words: patents that were published in 2010 will have had more opportunity to become cited then a patent application that was published in 2017. Therefore researchers look at the date of publication of the cited document to start the time frame.
That publication date is "the date that the information becomes prior art". (In whatever language that first publication occurred.) Because a publication date is still "application" bound (and not family based), one could use the date of the earliest publication of a simple family.

Re: forward citation (Families)

Posted: Mon Nov 19, 2018 12:53 pm
by Pasdeprenom
Thank you so much.