Via 100 entries or "mini-chapters," the SAGE 21st Century Reference Series volumes on Communication will highlight the most important topics, issues, questions, and debates any student obtaining a degree in the field of communication ought to have mastered for effectiveness in the 21st Century. The purpose is to provide undergraduate majors with an authoritative reference source that will serve their research needs with more detailed information than encyclopedia entries but not as much jargon, detail or density as a journal article or a research handbook chapter.