Reference year for 2yr_mean_citedness?

[Felix Schönbrodt]

Dear OpenAlex team,

I wonder what the reference year of the 2yr_mean_citedness (aka. impact factor) in the summary_stats is: 

"number of citations received in year X for publications in that journal that were published in the two preceding years"

Is X the current year? And if yes, is the number regularly updated?

When I compute it manually, my numbers are close, but not identical. Probably it depends on what publications are regarded as "citable items".

I could not find documentation about the specific computation of the 2yr_mean_citedness - it would be great if you could share/document that.

Thanks,

Felix

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Prof. Dr. Felix Schönbrodt
Ludwig-Maximilians-Universität München, Germany

Managing Director of the LMU Open Science Center | http://www.osc.lmu.de
Psychological Methods and Assessment, Department Psychology | https://www.psy.lmu.de/pm/personen/lehrstuhlmitarbeiter/schoenbrodt/index.html 

[Jason Portenoy]

Hello Felix,

The reference year is the year prior to the current year. So right now, we are using 2022 for the citing articles, and 2020-2021 for the relevant cited publications.

We've updated the documentation to clarify this. For example, https://docs.openalex.org/api-entities/sources/source-object#summary_stats

We precalculate these numbers and update them regularly (once per week), but these stats should remain relatively stable.

Cheers,

Jason Portenoy