***** To join INSNA, visit http://www.insna.org ***** Dear All, Although I am far from expert, it also struck me, reading: Evans, K. M. (1962) Sociometry and Education, The International Library of Sociology and Social Reconstruction (London: Routledge and Kegan Paul). that the routine collection of negative tie information seems to have declined. For school children, I can see that there would be ethical issues. (What do you do if you discover everyone hates Johnson?) It is hard to see that these negative ties would not have significant effects in real networks and thus that models not dealing with them would be in some way inadequate. All the best, Edmund -- Edmund Chattoe-Brown (Department of Sociology, University of Leicester, UK) [log in to unmask] -- http://www.fastmail.fm - A no graphics, no pop-ups email service _____________________________________________________________________ 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.