Information Technology Reference
In-Depth Information
-1
35% none
49% one
-2
9% two
-3
-4
3% three
-5
2% four
-6
1% five
-7
1% six or more
-8
0
0.5
1 1.5 2
Number of Citations (log)
2.5
3
Figure 1.11.
The number of scientific papers having a given number of citations. This is averaged over all
scientific publications for one year and the average number of citations of a paper is 3.2 per year.
Adapted from [
9
].
A frequent criticism of a paper in science is that it has only a few citations. In the
world of Gauss this would be devastating because the paper would be average and we
all know the value of being exceptional. The decision regarding whether to award tenure
to a junior faculty member often rests on such tenuous evidence of scientific ability as
the number of citations to published papers. In the real world, however, having the
average number of citations means that such a paper is in a category shared by only
the top 4% of the world's scientific publications. So the average paper is produced by
the exceptional scientist.
The first monograph to recognize the importance of inverse power-law distributions
in the natural, social and life sciences and to attempt their systematic explanation was
George Kingsley Zipf's
Human Behavior and the Principle of Least Effort
[
42
]. This
remarkable topic had the subtitle
An Introduction to Human Ecology
, which indicates
that the author put human behavior in the same category as that in which scientists
traditionally put other naturally occurring phenomena, that is, natural science
.
In other
words he was attempting to uncover the natural laws governing human behavior and
articulate their underlying principles by examining and interpreting data. In his preface
Zipf offers a word of caution that is as salient today as it was in 1949:
Nor are these principles particularly out of place at the present time, when we seem to be faced
with an impending planned economy in which a few persons will tell many others how they
should behave
- often perhaps without regard to how people
do
behave.
As the title of his topic implies, Zipf offered the principle of least effort as the primary
principle that governs individual and collective behavior of all kinds and his topic was
devoted to presenting the empirical data supporting his hypothesis, clearly explaining
the implications of his hypothesis and making the underlying theory logically con-
sistent. Zipf saw people as being in continuous motion and, in selecting the path of
their activity, viewing their decisions against a perceived background of alternatives.
He hypothesized that they decided on their paths in such a way as to minimize the
