On Mar 25, 2011, at 1:40 PM, Keith Jenkins wrote:

>> For a good time I geo-located the email domains of Code4Lib subscribers, plotted them on a Google map, and discovered that us Code4Libbers use Gmail in greater proportions than a couple of my other mailing lists (NGC4Lib and Usability4Lib) -- http://bit.ly/hdL55U  Interesting!?
> 
> While you're at it... what's the percentage overlap between those lists?


Using the list of subscribers as input instead of domains, I wrote a Perl hack (evaluate.pl) to answer the overlap question. [1]

$ ./evaluate.pl 

          Code4Libbers = 1706
           NGC4Libbers = 2115
           union (all) = 3394
   intersection (both) = 427

   percent in Code4Lib = 25%
    percent in NGC4Lib = 20%

In other words, there are 1,700 of us Code4Libbers and there are 2,100 NGC4Libbers. Not counting duplicates, the population of both lists is 3,400. Four hundred (400) of us are on both lists. Consequently, 25% of us subscribe to NGC4Lib and 20% of NGC4Libbers subscribe to Code4Lib. 

BTW, over the past year or so, the Code4Lib list continues to grow by one or two people per week, while the NGC4Lib list has seemingly reached a plateau. 

[1] evaluate.pl - http://bit.ly/eQKqH6

-- 
Eric Morgan