<qa>  What is the purpose of this research?The purpose of this research is to gain insight into the way in which physicians adopt new practice techniques. In particular, we are interested in how medical innovations diffuse throughout social networks. We wish to examine the diffusion of Low Molecular Weight Heparin LMWH use for Deep Vein Thrombosis DVT throughout the social network of general internal medicine interns, residents, and attendings at the University of Chicago Hospital. In numerous clinical trials, LMWH has been demonstrated to be as effective as unfractionated heparin as a bridge to long-term anticoagulation therapy with Coumadin, with the added benefit of early discharge from the hospital with easy dosing, no need for monitoring, and home therapy. A DVT critical pathway was established at the U of C in 1998, and LMWH was used off-label for that purpose beginning in 1997. However, it is unclear how quickly the use of LMWH was adopted by the physicians on the general medicine services, or whether there exists a pattern for this adoption. 