Length of Your Review

A question posed to me recently asked about the best length for a manuscript review. Let me quote from the email:

“On one side of the spectrum is a group of people that will only comment if something is blatantly wrong. On the other side of the spectrum is the reviewer that will give a lengthy response including all of the changes that could improve the study (or at least as improve the study in the eyes of the reviewer).”

Neither of these extremes is optimal. A very short, highly negative review is particularly bad but close behind is a very short, highly positive review. The more details I have, the better that I can assess the manuscript and weigh the recommendations from the two reviewers. So, in general, I like longer reviews. Reviewers can, actually, go too far, suggesting additional studies and analysis that might be very good to conduct but are not necessary for publication of the submitted manuscript. To me, an optimal review includes praise of the good parts of the paper, identification of what is wrong or unclear, and suggestions for what will make the study publishable.

As I said in one of my first posts on this blog, please be thorough – I like the longer reviews better than the short ones. If you need to write several paragraphs to explain why some aspect of the study is off base, then please do it. That helps me make the right decision about the manuscript.

The main place that I find reviewers being too verbose is with suggested new work. If you write two paragraphs on how the authors should really include another section, then please stop and ask yourself: is this new section that I am asking for necessary to make the submitted manuscript acceptable for publication? If not, then your two paragraphs are really a suggestion for future work. Such suggestions are fine but it should be noted as such. If not noted, then Editors and authors assume that it is a recommendation for acceptability, and authors should either do it or write a thorough rebuttal as to why they didn’t do it.

At the AGU reviewer resources page, the text begins with the main goal of peer review:

“AGU Publications relies on our reviewers to help ensure the standards, quality, and significance of our papers.”

Ensuring the standards, quality, and significance of papers in AGU journals is, I think, best served by identifying those elements of the manuscript that make it fall short of being a “significant contribution to the field.” A terse report, positive or negative, is less than fully helpful to me as an Editor. Similarly, it is useful to expand, at least somewhat, on the positive elements of the manuscript that raise it to the level of acceptability.

Down the page a bit is this definition of a good review:

“In general, the most helpful review is one which first provides an overall summary of the main contribution of the paper and its appropriateness for the journal and summarizes what major items should be addressed in revision.”

I agree. A very brief summary of the paper is always appreciated, not only for the Editor but also for the authors, so that they know that you understood the main point of the paper. Positive comments on the appropriateness for the journal are good, too, especially if the other reviewer finds fault with the same aspect of the manuscript. While many reviews include these elements, a large percentage of reviews do not, instead jumping in to the negative comments. Having these two other elements, a neutral paragraph reiterating the main point of the paper and a positive paragraph highlighting what is good about it, also helps to set a cordial tone to the report, which is always a good thing, in my view.

I like the figure in the Eos article about writing a good review, linked on this page.


It highlights that the first things a reviewer should write are these two elements, the summary and the positive aspects of the paper. Then move on to the concerns and suggestions.

This page also has a link to another page with the lists of questions and pull-down menus that reviewers will be asked as part of the submission of their report. This is not the full list of all things to consider in your review, but these are the questions that AGU would like to see answered about every manuscript sent out for peer review. Explanations of the answers to these questions should also be in the main text of the review.

So, longer reviews are, in general, better for the Editor. Just take this advice with some caution, however, and think twice about suggestions for new work. Make it clear in the report which suggestions are, in your view, simply possibilities for future investigations and which are recommendations for acceptability.


The Moldwin Paper on Citations

Mark Moldwin and I recently published a Commentary on, well, hopefully the title says it all: High-citation papers in space physics: Examination of gender, country, and paper characteristics. He obtained the article information for every paper published in JGR Space Physics in the year 2012, including the citation count as of June 2016 for each paper, and then classified the papers according to, you guessed it, gender, country, and paper characteristics. There were 705 papers in the journal that year, so this task took quite a while to complete, plus we took some time discussing which parameters to even classify for later use. We then analyzed these results to see which qualities about the paper had a statistically significant connection to citation count. A fairly recent year was deliberately chosen to investigate the factors related to citations early in a paper’s lifespan, a time interval of relevance to the calculation of the Journal Impact Factor. As of today, it is still “in press,” so just the accepted version is online, but the paper is Open Access so it is free to read the full text.


            Here are the major findings. These qualities of the paper are correlated with more citations in the first few years after publication:

  • More coauthors
  • More institutions in the author affiliations
  • More countries in the author affiliations
  • More references in the paper
  • A colon in the title

These qualities of the paper had no significant correlation with citations:

  • Gender of the first author
  • Number of words in the title
  • Acronyms in the title
  • Geophysical region names in the title

Keep in mind that the standard deviations are wide, so these findings are not necessarily true when comparing any two papers from the “high” and “low” classes. Welch’s t-test statistic uses the standard deviation of the mean, which is a much smaller number than standard deviation (the spread for any one data point in the set), Any individual paper, regardless of its characteristics, could have a high or low citation count a few years after publication. That is, we did not find a “magic parameter” that clearly identifies what will make a paper get many citations, nor one that easily picks out the low-citation papers.

Furthermore, the underlying distribution of values is not Gaussian – but any subset we considered, there is a long, positive tail creating a non-negligible skew to the histogram – yet the probabilities for significance that we used are based on a normal distribution for the two populations. This is why we used a 99% “highly significant” threshold to determine those qualities that are connected to citations.

So, take all of these findings with a grain of salt. Nevertheless, we think the results are interesting for the space physics community to know. The main conclusions that more authors, institutions, countries, and references increases eventual citations are not particularly surprising, but this is the first time it’s been quantified for papers in the field of space physics.

Two results are surprising to us. The first is that there is not a statistical difference in the citation of papers based on the gender of the first author. Other studies have found such bias in other fields, including in other closely related natural sciences, like astronomy. Unlike those studies of other fields, we did not find a statistically significant difference in citations to JGR Space Physics papers based on that parameter.

We did not expect to find any “title parameters” to be connected with citations and most were not. We were rather amused, however, to find that a colon in the title is linked to higher citations. About 20% of the papers that year had a colon in the title. That’s over 100 papers so this is a decently large sample size. We have guesses but, really, we have no good explanation for this. For those wondering, yes, this finding did indeed influence the title of our paper.

In summary, our advice to potential authors of manuscripts for JGR Space Physics is this: collaborate with others and cite the literature. It’s not a guarantee that your paper will receive above-average citations but, based on our analysis, it might help. Happy writing!

Preprint Servers: Challenges

A third (and probably final, for now) post on of ESSOAr, AGU’s new preprint server for Earth and space sciences. The first described it, the second touted it, and now this one is the ethical scold of how best to use it.

The biggest point to remember is that preprint servers are not peer-reviewed journals. Yes, there is an editorial board that checks submissions for scientific scope, but there is no vetting of the accuracy of the content. The editorial check takes a day or two, maybe a week max, but it is not a real review process. Yes, content here gets a DOI, but we should all remember that content on preprint servers are essentially just a step above “private communication” in terms of referencing authority. That is, it could be wrong.

We hope that content on ESSOAr, and any other preprint server, will eventually be published in a scientific journal. Researchers are putting their reputation out there with each new post on one of these servers, so the content is, for the most part, respectable. Go ahead and use it to learn what is being done by your colleagues. Because preprint server content has not been through the peer review process, though, it should be replaced with the “final” version of the study from whatever journal it eventually appears in.

To summarize in a graphic:


            Peer review should still be the standard for what is accepted as “knowledge” of the subject. Even this can be wrong but at least it has been thoroughly scrutinized by experts. You should be very skeptical of older preprints on the server (say, more than 2 years since original posting) that lack a link to a final published version of the paper. That work either was not submitted or did not pass peer review. If the former, then it is perhaps the case that the authors found a problem with the study and therefore never submitted that version of the paper. If the latter, then perhaps the editor or referees found a problem with the study and declined publication of it. Either way, the study did not reach its “final” form in the literature.

The advice to the community about older preprints can be summed up like this:

  • Authors: use caution when citing an older preprint.
  • Reviewers: pay extra attention to citations of older preprints.
  • Editors: ask reviewers to check the appropriateness of older preprint citations.
  • Societies: set policy about citing older preprints.

I am told that the astrophysics community, which regularly uses the arXiv preprint server, understands this difference in “publication” levels. That is, research communities can learn to use preprint servers and make it their go-to place for the latest content across a number of journals, as I am told that many in astrophysics do. They also know, however, that when it comes time to write your own paper, don’t rely on preprints as your main entries in the reference list. The astrophysics community, I am told, understands the guidelines about preprint servers and only uses it for finding the latest work on a topic.

We, the Earth and space science research community, should adopt this same mentality about preprint servers, not only ESSOAr but any server (and there are several being created). Such servers should be a place to get the latest studies from across a variety of journals, learning about content as the manuscripts are submitted rather than months later when they are accepted and eventually published. We should only use it for the latest work, though. A preprint server is not the place for full literature searches – those should be done in Web of Science, Google Scholar, Scopus, ADS, or other services that scan the published, peer-reviewed literature. And, as an editor, I strongly urge you to please conduct a full literature search, because a recent study by Mark Moldwin and me showed that the more complete your reference is, the more citations your paper will get (on average).

Use ESSOAr, but know its purpose within the hierarchy of scientific publications.

Preprint Servers: Benefits

With the launch of ESSOAr, AGU (and all of the other supporting societies on the advisory board) has entered the market of posting scholarly content prior to official acceptance by a peer-reviewed journal. Yesterday I discussed the “how” of ESSOAr, here I discuss the “why.”

The big reason is to increase scientific communication and collaboration. AGU’s mission is to promote discovery in Earth and space sciences, and many of the society’s honors, medals, and awards cite “unselfish cooperation in research” as a primary criterion for selection. Posting scholarly work to a preprint server increases its visibility and, hopefully, impact within the research community. It gets your findings into the hands of other scientists a bit sooner than normal – a bit closer to when the work was done rather than after months of reviews and revisions. It helps increase the “speed” of scientific discovery, as we learn about what’s new a little bit earlier than we would have from journals alone.

Here is the “why” answer from the ESSOAr FAQ page:


In addition to a lot of the same arguments I write above, there is an interesting comment in the middle of the paragraph, “You can establish priority.” Rather than the publication date being your time stamp laying claim so some finding, posting on a preprint server establishes that claim a bit sooner.

In a somewhat selfish consideration, the anecdotal evidence that I have heard is that posting your work on a preprint server increases the “early lifetime” citations to the paper. That is, it is thought that the page views and downloads of the preprint leads to faster incorporation of your findings in the work of other scientists, and citations to it therefore should begin a few months sooner. I am not sure how true this is, because the citation rate with year since publication is fairly constant at ~3/year in JGR Space Physics. Furthermore, I am told that the solar physics community extensively uses the arXiv preprint server, yet the journal Solar Physics has a Journal Impact Factor about the same or even slightly lower than JGR Space Physics. In support of preprint servers, I am told the astrophysics community uses arXiv even moreso that solar researchers, and The Astrophysical Journal has a JIF several points higher that the JIF for JGR Space Physics. So, perhaps my awareness of the solar community’s usage of that server is overestimated. This is all speculation, though; we need some quantitative statistics on usage and eventual citations to robustly claim anything. My point is that, while the evidence is mixed about the effectiveness of preprint servers, there is a plausible argument that they should lead to higher citations soon after publication.

Because it s really very little time and effort to upload, I think that it is worth it to do so. I suggest doing this when you submit to the peer-reviewed journal. I haven’t gone through it yet to see it for myself, but I am told that there is a link within the GEMS process for automatically sending the newly-submitted manuscript over to ESSOAr. The trickiest thing about submitting to ESSOAr was the license agreement. There are 4 levels of user licenses available to you. The most lenient is “CC-BY”, for which the only restriction is that users must properly cite it. For my Fall AGU poster, I selected the second level, “CC-BY-NC,” which places the additional constraint of no commercial reuse without my permission. The next level adds a restriction on “derivative use” without permission of the authors. The fourth one is the most restrictive and basically says it can be here on ESSOAr with no other use allowed. Aside from this, the process is very straightforward and easy.

The second step to achieving the full benefits of a preprint server is using ESSOAr as a place to learn about the latest results in your field. This requires signing up for new content alerts. Once you have logged in, conduct a search with some keywords of relevance to you. Once the results are up, then in the upper right area of the page is this:


The first link, the magnifying glass with the plus symbol, will “save the search” for you. This opens up a new window where you can name the search and indicate how often you want it to automatically run this for you and send you an alert about it. It looks like this:


The second symbol opens a page for setting up RSS alerts for the individual posters and preprints found in the search. Actually, both of these links are there regardless of whether you have signed in, you just can’t actually save the search until you log in.

On the page for each poster or preprint in the database, there are two links, “Track Citations” and “Add to Favorites.” The first allows you to get alerts on citations to that specific post, while the second just provides a quick link to that post. These settings, and the saved searches, can all be managed from your profile page. To get there, click on your name in the upper right corner and then on the “Profile” tab. On the new page that loads, the left-column menu has Alerts, Favorites, and Saved Searches.

There isn’t much content available yet – a handful of manuscript preprints and about 50 poster PDFs. If we all collectively start using it, though, then ESSOAr will blossom into a place where space scientists go to learn about the latest work being prepared for publication.

ESSOAr is here

The Earth and Space Science Open Archive is up and running. This is a new preprint server created under the leadership of AGU with technical and financial backing from Atypon and Wiley. Over a dozen scientific societies are participating in ESSOAr, advising on the development, structure, and policy of the site. It was announced in Eos back in September but it is now accepting submissions as of late January.


            In the middle of the central graphic on the website is a search tool, to browse what is already uploaded to this pre-publication archive. There are several space physics posters already in the system. Yes, posters. If a meeting is approved by the advisory board, and pretty much all AGU-related meetings should be approved, then those that presented posters at the meeting will be able to upload a PDF of their poster to ESSOAr. That is, ESSOAr is more than just a preprint server but is also filling a unique niche in capturing the scientific content of the conference poster hall and allowing for a virtual poster session after the meeting.

To add content, you first have to log in to the system, which is done with your ORCID username and password. This allows you access to the author dashboard link along the top menu bar. The author dashboard gives you a second menu bar across the top, like this:


showing you all of the stages of submitting a poster or manuscript preprint to the server.

I went through the submission process with my Fall AGU poster and it is fairly easy. I think the trickiest thing was picking a license agreement for it. ESSOAr offers 4 levels of license. In the footer of all pages, there is a link to a nice Frequently Asked Questions list available about ESSOAr. One of those questions is about the license levels. It’s good to read this first. All levels require users to provide proper attribution back to this ESSOAr posting, but some prohibit commercial or derivative use. It’s also good to read through the fine print at the user terms and conditions.

Material posted here is not peer reviewed. There is a long list of researchers on the editorial board that check to make sure that submissions are within the scope of scientific endeavor appropriate for inclusion in the server. They do not, however, offer corrections or suggestions to the material. That’s on you.

Once something is posted, you can “revise” but not delete it or remove it. This is probably not needed for poster submissions, but manuscript preprints could be revised with subsequent iterations of the paper. Once published a link to the journal version of the manuscript should be added to the ESSOAr version.

Like preprint posts to arXiv, preprints put here are excluded from the similarity cross-check conducted on all manuscript submissions to AGU. In fact, AGU is making it easy for authors to upload to ESSOAr and then “transfer” some of the information you just typed over to a formal submission to an AGU journal. And the reverse, too: submission to GEMS will now have a link to also post on ESSOAr.

I’ll have other posts on the benefits and challenges of preprint servers. For now, happy posting.