h value

March 24, 2006 at 2:39 am | | everyday science, journal club, literature, nerd

I presented a paper at my Chemical Physics Journal Club a while back. Here’s a citation: Hirsch, J. E. An index to quantify an individual’s scientific research output. Proc. Nat. Acad. Sci. 2005, 102(46), 16569–16572.

The basic idea is that h measures your (career) scientific output, the higher the value, the greater the output (convolved with impact). h is the number of papers that you have authored, each with h or more citations. In other words, if you have 50 papers, but only 30 of them have been cited 30 or more times, your h = 30. This method tries to avoid giving a lot of credit to people who write oft-cited review articles or people who write millions of papers that no one ever reads.

It’s mostly sorta bullshit, but I enjoyed calculating the “h value” (or “h index” or “h number” or “Hirsch number” or…) of several of the profs at Stanford:

PI h
Pande 28
Moerner 43
Andersen 48
Fayer 51
Boxer 52
Zare 94

But there are some things that are unfair: Pande is a younger scientist, so he hasn’t had as much time to publish or have his works cited as, say, Zare or Fayer. So we can normalize to the number of years since earning PhD (where m = h/#years):

PI m
Andersen 1.2
Fayer 1.6
Boxer 1.7
Moerner 1.9
Zare 2.2
Pande 2.5

Comparing m values is probably a little more fair. But now there are some more problems. Pande is in his steep period, which will presumably level off like this:


So you get your PhD, then you die. The value of m also doesn’t take into account that Andersen is a theorist or that W.E. spent until the mid-90s in industry, where people normally don’t publish as much. Oh well, it’s still pretty fun.

By the way, hsam = 1

UPDATE: Check out my new measure, the Lord h-bar index.


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  1. […] also make complex decisions about the …www.nap.edu/readingroom/books/obas/contents/values.htmlEveryday Scientist » h valueBut there are some things that are unfair: Pande is a younger scientist, so he hasn’t had as much […]

    Pingback by what are the values of a scientist: Web Search Results from Answers.com — June 19, 2007 #

  2. there was a nature paper published on the subject as well…a couple of years ago.
    i cannot find it now, sorry to be almost helpless

    Comment by armando — June 22, 2007 #

  3. […] databases, notably ISI Web of Science, are really great at finding H-index values or citation trends. But, when I really want to do a lit search on a topic or reaction, SFS […]

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  5. […] commented a while ago about the Hirsch h index. In fact, it was one of my first posts 2.5 years ago. Since then, the h index has become […]

    Pingback by Everyday Scientist » new citation index: the h-bar value — October 9, 2008 #

  6. what is my h-index? thank you

    Comment by r.gakhokidze — April 17, 2012 #

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