Archive for NASA/SAO Astrophysics Data System

Alternatives to Scopus

Posted in Open Access with tags , , , , , on August 7, 2025 by telescoper

Yesterday I had a very interesting meeting with the Library Staff who are working behind the scenes on the Open Journal of Astrophysics. Most of the meeting was about reviewing the finances of the journal, so I had a look at the official accounts. These confirmed that the total cost incurred is under $30 per paper. The financial year here at Maynooth runs from October 1st to September 30th – don’t ask me why – so this year is not yet complete but will be just over $5000 dollars. We will have published about 180 papers in that period.

People ask me how the journal can be so inexpensive, and the answer is that we keep publishing costs to a minimum by offering a “no frills” service, and also because our editors and referees are all unpaid.

Anyway, in the course of the meeting I mentioned Scopus (which is owned by publishing behemoth Elsevier). This is used by many universities and funding agencies as a source of bibliometric information, but my experience is that it is unreliable and poorly managed. I thought I would share a few other, better, bibliometric databases here.

We have for some time being indexed in the Directory of Open Access Journals (DOAJ) and in fact our articles’ metadata are automatically deposited there every time we publish a paper. This however only covers fully Open Access journals which excludes some journals.

The go-to repository for astrophysicists is the NASA Astrophysics Data System, known to its friends as ADS. This has very complete bibliographic information going back over 100 years, as well as links to catalogues and other supplementary information. It’s also fairly complete for general physics.

Scopus being so awful I was pleased to find a system which is more general than NASA/ADS but with wider coverage. OpenAlex fits the bill rather well. It’s not quite complete but far better than Scopus. Articles from the Open Journal of Astrophysics are index there, and the information is almost as complete as NASA/ADS.

One candidate is Scimago. This is largely concerned with the (in my opinion) pointless task of journal rankings, but the Open Journal of Astrophysics is listed there. Again the information is not totally complete, but it’s not bad.

One thing I’ve learned over the last few years is that if you want to compare the impact of journals or individual articles it’s absolutely essential to use the same source of information because there is a huge variation between databases. When I look at astrophysics articles I always use NASA/ADS, but in other fields you could use OpenAlex or Scimago. There are no circumstances that justify the use of Scopus, even if your boss tells you to…

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ADS and the Open Journal of Astrophysics

Posted in Open Access with tags , , , , , on January 19, 2020 by telescoper

Most if not all of the authors of papers published in the Open Journal of Astrophysics, along with a majority of astrophysicists in general, use the NASA/SAO Astrophysics Data System (ADS) as an important route to the research literature in their domain, including bibliometric statistics and other information. Indeed this is the most important source of such data for most working astrophysicists. In light of this we have been taking steps to facilitate better interaction between the Open Journal of Astrophysics and the ADS.

First, note that journals indexed by ADS are assigned a short code that makes it easier to retrieve a publication. For reference, the short code for the Open Journal of Astrophysics is OJAp. For example, the 12 papers published by the Open Journal of Astrophysics can be found on ADS here.

If you click the above link you will find that the papers published more recently have not got their citations assigned yet. When we publish a paper at the Open Journal of Astrophysics we assign a DOI and deposit it and related metadata to a system called CrossRef which is accessed by ADS to populate bibliographic fields in its own database. ADS also assigns a unique bibliometric code it generates itself (based on the metadata it obtains from Crossref). This process can take a little while, however, as both Crossref and ADS update using batch processes, the latter usually running only at weekends. This introduces a significant delay in aggregating the citations acquired via different sources.

To complicate things further, papers submitted to the arXiv as preprints are indexed on ADS as preprints and only appear as journal articles when they are published. Among other things, citations from the preprint version are then aggregated on the system with those of the published article, but it can take a while before this process is completed, particularly if an author does not update the journal reference on arXiv.

For a combination of reasons, therefore, the papers we have published in the past have sometimes appeared on ADS out of order. On top of this, of the 12 papers published in 2019, there is one assigned a bibliometric code ending in 13 by ADS and none numbered 6! This is not too much a problem as the ADS identifiers are unique, but the result is not as tidy as it might be.

To further improve our service to the community, we have decided at the Open Journal of Astrophysics that from now on we will speed up this interaction with ADS by depositing information directly at the same time as we lodge it with Crossref. This means that (a) ADS does not have to rely on authors updating the arXiv field and (b) we can give ADS directly information that is not lodged at Crossref.

I hope this clarifies the situation.

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