WordSift was created by Kenji Hakuta under a grant from the Council of Great City Schools. The website was programmed by Gregory Wientjes, a doctoral student at Stanford University. Diego Roman and Karen Thompson, both doctoral students at Stanford and former teachers, provided support and feedback in developing usage features. The project profited enormously from collaboration with teachers at San Francisco Unified School District that was supported by the Strategic Education Research Partnership (SERP). We especially acknowledge the support of Phil Daro (SERP Site Director), Tina Cheuk (SERP Associate Director), and colleagues from UC Berkeley also involved through SERP: David Pearson and Marnie Nair. We gladly express our appreciation to the middle school science teachers as well as the administrative support team with whom we continue to engage in developing WordSift: our teacher collaborators were Joel Austin, Karen Clayman, David Brody, Lisa Ernst, Michael Fox, Patricia Kudritzki, Sally Meneely, Stephie Prout, and Lisa Beth Watkins; administrative support was provided by SFUSD Middle School Science Curriculum Specialist Deborah Farkas, Mathematics and Science Supervisor Jeanne D’Arcy. The project also gratefully acknowledges our predecessors and colleagues in word cloud technologies, including Tag Crowd (Daniel Steinbock), Wordle, WordNet (thanks, George!), and Visual Thesaurus.