Liu Tieying has been studying on language and characters for years. Liu was a reporter and an editor. He has been working on Teaching Chinese as a Foreign Language since 2003 and taught foreigners Chinese at Beijing Normal University, US Foreign Service Institute (FSI) and Beijing Language and Culture University. Wang Xinmei has been working on Chinese teaching and research for years. She is now a researcher on Teacher Training, Teaching Chinese as a Foreign Language and a tester on Chinese proficiency level at Beijing Municipal Language Affairs Committee. She has published tens of papers on linguistic journals and compiled some books on language and characters.