In measuring the Gender Diversity Index (GDI), we don’t have access to gender information, so we tag the gender most associated with a given first name. Thus, the number of species is 2: male and female.

We calculate the GDI following the Shannon evenness [1] (we discard richness) by means of the Pielou’s diversity index [2]:

H’ is the Shannon diversity index [1] and H’max is the maximum possible value of H’ (if every species was equally likely):

p is the proportion (n/N) of individuals of one particular species found (n) divided by the total number of individuals found (N), and S, that is the number of species.

J’ is constrained between 0 and 1, meaning 1 the highest evenness.

For calculating the Gender Diversity Index, we should consider three different communities: keynotes, authors (of the 10% of the papers) and organisers. Our final Gender Diversity Index performs a weighted average among the Pielou’s evenness index in each community, giving more the highest priority to keynotes (they get more visibility) and less priority to organisers (they get lower visibility):

References:

[1] E. C. Pielou. The measurement of diversity in different types of biological collections. Journal of theoretical biology, 13:131–144, 1966.

[2] C. E. Shannon. A mathematical theory of communication. Bell system technical journal, 27(3):379–423, 1948