A research agenda has been at the core of "Sesame Street" and other Children's Television Workshop (CTW) educational projects since inception. This collection of presentations, from a symposium honoring the twentieth anniversary of Sesame Street's debut on national television, addresses research's role in the series, describing how research is used during preliminary development of shows, continues during production, and allows measurement of a new program's success as a teaching tool. The collection's contents are: (1) "Prologue" (David Britt); (2) "Welcome" (Gregory R. Anrig); (3) "Beginnings" (Gerald Lesser); (4) "Creating CTW's Research Arm" (Edward L. Palmer); (5) "The First Evaluation" (Samuel Ball); (6) "Subsequent Research" (Gerald Lesser); (7) "Cognitive Effects of Sesame Street" (Daniel R. Anderson); (8) "Social and Emotional Effects of Sesame Street" (Aimee Dorr); (9) "Message Design Issues in Sesame Street" (Milton Chen); (10) "Current Research" (Keith Mielke); (11) "Longitudinal Study of Sesame Street Effects, Part I" (Aletha Huston); (12) "Longitudinal Effects of Sesame Street Effects, Part II" (John Wright); (13) "Educational Effects of Sesame Street Home Videos" (Mabel Rice); (14) "Continuing Evolution of the Sesame Street Curriculum: The Role of Formative Evaluation" (Valeria Lovelace); (15) "Other Current Studies" (Keith Mielke); (16) "International Research" (Gerald Lesser); (17) "Introductory Remarks" (Lutrelle Horne); (18) "A Review of Research on International Coproductions of Sesame Street" (Peter Levelt); (19) "Research on 'Iftah Ya Simsim', the Arabic Coproduction" (Abdelkader Ezzaki); (20) "Research on 'Rua Sesamo', the Portuguese Coproduction" (Maria Emilia Brederode); (21) "Research on 'Susam Sokagi', the Turkish Coproduction" (Nail Sahin); (22) "What Lies Ahead" (David Britt); (23) "A Walk down Sesame Street" (Lewis Freedman); (24) "Challenges Met and To Be Met" (Lloyd Morrisett); (25) "Closing" (David Britt); (26) "20 Down, at Least 20 To Go" (Joan Ganz Cooney); and (27) "Epilogue" (Gregory R. Anrig). Two Appendices list symposium special awards and participants. (EV)