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Activity index by citation class

Definition

This indicator quantifies the relative presence of the publications of an actor compared to the publications within the same frame of reference, in terms of their visibility (number of citations).

Six classes of publications are delineated by OST by the number of citations received by a publication:

  • Class 1: the top 5% most cited articles worldwide
  • Class 2: the next 5% most cited articles
  • Class 3: the next 10% most cited articles
  • Class 4: the next 20% most cited articles
  • Class 5: the next 20% most cited articles
  • Class 6: the 40% least cited articles

The indicator activity by citation class (expressed as a positive number) is defined for each of these classes as:

the share of publications that an actor (institution, country, etc.) places in the class in question (for a given time period) proportional to the share of all publications within the frame of reference (world for example) for the same class.

N.B. When the index of activity for a certain citation class is greater than 1, the actor is more present than the average actor of the frame of reference in the same class.

 

Example

Table 1-3-53
France : scientific publications – activity index by citation class and by field (2003)

Click to enlarge (taken from the OST Report – 2006 edition)

Interpretation: Over a period of two years, the activity index for France for all fields taken together is greater than the world average, for the first five citation classes. It is about 1.08 for the first three classes, the top 20% of articles the most cited worldwide. It is near the world average for the next two classes. In the last class, covering articles not often cited, the activity index for France is below the world average (0.96). In Applied Biology / Ecology, followed by Earth Sciences, Astronomy and Astrophysics, and Engineering, France makes the strongest showing in Class 1 or the 5% most often cited articles in the world. In this same class, French research also makes a stronger than world showing in Physics (1.14), Mathematics (1.14) and Biomedicine (1.04).