The diffence between AC and the sum of fractioonal count for collaborative paplers involving the named country and partners
About Table of top 100 countries by collaboration score. I suggest Nature to explain better what is means "The score for country A = sum of all FCs for country A and all its collaborating countries". Is the same of AC? Because in the table of 2014 Nature team use AC and in the table of 2015 the author uses Weighted Collaboration Score. Are they the same kind of date? If is not, is not clear for me, what is the difference? Thanks
By “The score for country A = sum of all FCs for country A and all its collaborating countries", we are referring to the sum of FCs for all the bilateral relationships a country has.
So for example, if country A has relationships with 2 others, B and C, then the collaboration score is the sum of FC for A+B and A+C. In other words, if Brazil only collaborated with Argentina and Chile then the collaboration score for Brazil would be: (FCBrazil+FCArgentina)+ (FCBrazil+FCChile).
The weighted collaboration score uses the same calculation, but is based on WFC instead of FC.
AC stands for Article Count, which we use for direct output (not collaborations) and which is not used in the collaboration supplement. It refers to the number of papers a country (or institution) has published in the Nature Index.
In the 2014 supplements you are referring to, we have been looking at direct output only and not collaborations. We use these three measures for direct output:
AC (article count >> number of articles)
FC (fractional count >> the actual contribution to an article)
WFC (weighted fractional count >> applies a weighting to the FC to address an overrepresentation of astronomy and astrophysics papers)
The collaboration supplement last year is looking at collaborative output rather than direct output, so we are using a different measure ‘collaboration score’. Collaboration score has nothing to do with AC.