***** To join INSNA, visit http://www.insna.org ***** My understanding is that it is one purchasER -- a nice two-mode network: set(ego,[purchase1,purchase2, ... , purchaseX]). Think of the famous two-mode data set: 18 Southern Women. Instead of deriving how the women are connected, Amazon looks at how the events they attended are connected. Here is a great paper by Lin Freeman on the Southern Women data set... http://moreno.ss.uci.edu/85.pdf Valdis On Jan 3, 2007, at 12:22 PM, Neil Eckardt wrote: > Does Amazon make public how they construct > the consumption networks we see? Is it simply one purchase that > ties two books together? _____________________________________________________________________ SOCNET is a service of INSNA, the professional association for social network researchers (http://www.insna.org). To unsubscribe, send an email message to [log in to unmask] containing the line UNSUBSCRIBE SOCNET in the body of the message.