We used an early beta of The Microsoft Academic Knowledge API to see if we could quantify the emergence of academic clusters of excellence in small subfields. Our Academic Innovation Clusters visualisation tools and the our openly documented methodology have since informed further tools and techniques.
In the example below we see that Big Data as a field (left) is a much more recent phenomonem than Artificial Intelligence (right).
Since publication, the Microsoft Academic Knowledge dataset has improved enormously, and been supplemented by other great data sources. All are part of The Data City.