The question is motivated by the fact, that Physical Review Research still did not get its first impact factor and a date it happens given on their internet page:

"We are hopeful that Physical Review Research will be fully indexed soon and will receive its first Impact Factor in June 2021"

was changed to June 2022.

  • I am just guessing so not posting an answer, but an impact factor is based on the number of times papers published in the journal are cited. It takes time (many years probably) to gather enough statistics to reliably determine an impact factor.
    – Louic
    Commented Jul 2, 2021 at 9:02
  • I think the number of years one needs to give the impact factor is fixed, as only the two years before the publication counts for calculating it. Accordingly, I do not see how the date can be suspended as one knows that after I think 3 years one can calculate it. The other issue would be if one would classify the journal as predatory, then no impact factor is calculated. But I very doubt it was here the case, this is why I restrict in my question to journals from "prestigious publishers".
    – Agnieszka
    Commented Jul 2, 2021 at 9:27
  • If the total number of "citable items" is low in the first years, the impact factor would not be very accurate.
    – Louic
    Commented Jul 2, 2021 at 10:23
  • This is true, but does it prevent inclusion in the Journal Citation Report and calculation of the impact factor? Is there any threshold in number of publications a journal has to reach? I somehow cannot imagine that even it is so, the Physical Review Research did not reach this threshold, as for some initial time there was no publication fee for it.
    – Agnieszka
    Commented Jul 2, 2021 at 10:48
  • Note that the first articles in PRResearch were published in August 2019, so it actually hasn't been two full years yet.
    – Anyon
    Commented Jul 2, 2021 at 14:00

2 Answers 2


I don't think anything has been "suspended." Physical Review Research is still listed in the Emerging Sources Citation Index (ESCI), which is where most or all new journals start nowadays. Journals listed in ESCI don't receive an impact factor. Only when the journal is transferred to the Science Citation Index Expanded can it receive an impact factor.


This one is fairly obvious. The journal wasn't good enough to be indexed by Clarivate (the company that manages the Science Citation Index and calculates the impact factor) in 2021, hence the journal is hoping to be indexed in 2022 when Clarivate do next year's assessment.

For clarity, a lot of things are needed before one can get indexed by Clarivate. There are over 25 criteria. Some of them are not obvious, such as:

The authors must have affiliations, geographic diversity, and publication records that validate their participation in the scholarly community associated with the stated scope of the journal. The demographic of the contributing authors should be consistent with the topical and geographic characteristics of the Editorial Board.

Other criteria are practical:

Cited references, names, and affiliations must be published in Roman script to allow rapid, accurate indexing, and easy comprehension by our global users.

And some can cause serious headaches for new publishers:

The journal must provide a readily accessible, clear statement of the commitment to peer-review and/or editorial oversight of all published content. Primary research articles must be subject to external peer review.

It's improbable APS will screw up the latter two of these examples because they've have done them before for other journals, but the first is not something that's within their direct control, and that could have caused the application to fail.

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