The Science Working Group (SWG) is a committee appointed by NASA Headquarters to provide guidance on the science goals and capabilities of JWST. The JWST Project office holds the official SWG Charter (PDF). White papers describing science programs that might be accomplished with JWST have been written by SWG members and other scientists.
The SWG consists of Ex Officio representatives of the three space agencies, the Lead Investigators of the science instruments and six competitively selected Interdisciplinary Scientists. This link provides the full list of SWG members. To send questions or comments to the Webb SWG, please contact firstname.lastname@example.org.
The SWG was preceded by the Ad hoc SWG (1997-2000) and the Interim SWG (2000-2001). These links provide Charters, Memberships, Meeting notes and other documents produced. The ASWG has been especially instrumental in creating the Design Reference Mission (DRM), a sample of core science programs used to test NGST designs.