# Michael S. Rosenberg’s Laboratory

Computational Evolutionary Biology & Bioinformatics

E-mail: msr@asu.edu
← Back to introduction

## collaborative index

The Collaborative Index (Lawani 1980) is a basic measurement of the degree of collaboration within a set of publications. It is calculated as:

$$\text{CI}=\frac{\sum\limits_{a=1}^{a_\max}{af_a}}{P},$$

where fa is the number of publications having a authors and amax is the largest number of authors for any publication.

### Example

 # of Authors (a) # of Publications (fa) Product (a×fa) 1 2 3 4 5 3 3 5 5 6 9 20

The sum of the products is 40, which yields a collaborative index of 2.5 when divided by the total number of publications (16).

YearCI
19973.0000
19982.8333
19993.0000
20002.8333
20012.5000
20023.1500
20033.3750
20043.3333
20053.0312
20063.0000
20072.9444
20083.0000
20092.9048
20103.5625
20113.5000
20123.4906
20134.0000
20143.9016
20153.9206
20163.9538
20174.0597

## References

• Lawani, S.M. (1980) Quality, Collaboration and Citations in Cancer Research: A Bibliometric Study (doctoral dissertation). Florida State University: Tallahassee, Florida.