What exactly is impact factor?

[toofastdan]

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I realize the words "impact factor" are mentioned quite a bit when talking about publications. What exactly constitutes a journal's impact factor and what is considered high impact? Is there a certain threshold like > 10? Also, does impact factor depend on the research field?

I know that publications are not required for MD/PhD admissions, but I want to get an idea on how programs view papers and author position. How would programs view a first-author paper in a mid-IF journal vs a mid-author paper in a high-IF journal?

I appreciate the consideration!

 

[MSTPadvocate]

Impact factor is the number of times a paper is cited in the two years after publication. Its a meaningless stat that can be manipulated by publishing review articles in the journal or by making authors cite works from that journal. The problems with it are myriad, yet it persists:

What’s wrong with the journal impact factor in 5 graphs

Scholars love to hate the journal impact factor, but how flawed is it?

www.natureindex.com

 

[MSTPadvocate]

I realize the words "impact factor" are mentioned quite a bit when talking about publications. What exactly constitutes a journal's impact factor and what is considered high impact? Is there a certain threshold like > 10? Also, does impact factor depend on the research field?

I know that publications are not required for MD/PhD admissions, but I want to get an idea on how programs view papers and author position. How would programs view a first-author paper in a mid-IF journal vs a mid-author paper in a high-IF journal?

I appreciate the consideration!

and personally, I would consider a first author publication much, much, much, much more highly than a mid-author publication regardless of the journal.

 

[inode]

^I disagree slightly. A first author publication in a potentially predatory journal (or a very low-tier journal) that uses t-tests to identify genes that change between normal tissue and diseased tissue isn't going to really benefit anyone when it comes to MSTP programs. A fourth author Science paper would be far more meaningful than that.

If it were between a first author PNAS-tier paper and a fourth author Science paper, then that's a different story.

From my anecdotal experience, it seems that the ability to discuss your research well + letters of support from your PI play a far bigger role than publications (because publications are dependent on many things that are not under the control of the student). Many people who get into top 10s have zero publications (or perhaps only have a biorxiv submission) but they're generally able to discuss their research well, can describe why their research is valuable, have strong rec letters, are working on a paper (and have written proposals, are writing a thesis, etc.), among other things (gpa, mcat, some luck, etc.).

Regarding impact factor, what matters more is how scientists generally perceive journals. Yes, Nature, NEJM, JAMA, Lancet, Science, and Cell -- everyone has heard of those (and those journals' reputation) so they are automatically considered high-impact. People would consider PNAS, eLife, Cell Reports, Nature Communications, etc. to be fairly prestigious but not as high as those other journals mentioned previously. And a journal like peerJ would be considered less prestigious than all those mentioned previously.
Impact factor tends to correlate with journal prestige but it is a flawed metric, albeit not a meaningless one (I look up journal impact factors all the time to get a rough idea of how the journal is before bringing up the journal with my colleagues to see what they think).

 

[Neuronix]

I personally like to see what trainees are doing as first author. This implies that they actually did a majority of the work themselves.

People get added as middle authors on stuff all the time for all sorts of political reasons. It doesn't mean that they actually meaningfully contributed or have any real potential for significant scientific contribution and leadership in my opinion.

Impact factor is pretty meaningless for evaluating an undergrad. That's more of a reflection of whatever lab and project you happened to land in.

 

[SurfingDoctor]

Impact factor is a reflection of how many citable review articles and position papers a journal publishes...

 

[inode]

I still stand by my original views.

My best works to date are those that I'm not first author on and I'm proud to have been a part of those projects (where I made a strong independent contribution to).
As a young trainee, I don't exactly get the latitude to spend money on huge mouse experiments or sequencing experiments or a risky genetic screen, nor do I have the skillset/capacity to make a groundbreaking discovery (compared to full-time grad students and postdocs).

While it may be true that "People get added as middle authors on stuff all the time for all sorts of political reasons", that doesn't mean that "all middle authors are only there because of political reasons".

As for "Impact factor is pretty meaningless for evaluating an undergrad. That's more of a reflection of whatever lab and project you happened to land in", I can make the same argument for first-authorships. Many professors aren't going to let an undergrad publish a low-impact paper with their names associated with it just because it helps the undergrad get into medical school.

There are certainly important things that you can learn from driving your own low-impact first-author project, but there are also many important things that you can only learn from being on big high-impact projects with senior grad students or postdocs. I've done both and I don't want to see the latter de-valued; because that's honestly how I developed the most as a scientist.

I'm very against the "it's better to publish first-author regardless of the journal" idea because it encourages sloppy science and encourages publishing in journals with lax peer review standards.

I still believe that other factors matter more than getting published. My arguments are not without merit; just look at the MSTP website for the top 10 programs and look up some students; many students have zero publications and very few actually have a first-author paper.

My personal take-home message: Focus on doing good, honest science and drop all the fussing over impact factor and authorship position. If you can get your good, honest science published, that's a plus in itself.

 

[Neuronix]

These are personal opinions and they reflect the reality of MD/PhD admissions. Adcoms come with a lot of different viewpoints, and how things in your application are weighted depends on the institution and often upon the individual reviewer who gets your file. This accounts for much of the "randomness" that is seen in admissions.

 

[gbwillner]

Science and Nature are full of examples where they rejected submissions that were actually paradigm-shifting, seminal works. Some labs will ONLY publish in Cell, Science, and Nature; others leave it more to the trainee to decide. I don't think, as Neuronix stated, there is a right answer to where you should submit or how anyone will receive and process this information.

My advise is that everything matters to some degree. No one will look at one factor to the exclusion of others. I gave a negative review once to an applicant that had 5 first-author Nature papers for a PSTP position. The PAPERS were impressive, but it was not clear the applicant had much say or responsibility for any of the works performed and they really reflected what their large and influential lab was doing. Showing independence in thinking, executing, and writing the work is most important to me, but this may not be universal. If you can do this in a Nature paper, then awesome. If you can do it in Clinical Chemistry then OK, that's pretty good too. If it's self published and not peer-reviewed... OK, that's not OK.