One criticism of school-based instruction is the use of outdated teaching methods and contents to equip current students for future society. School teachers in the 21st century need to be equipped with professional teacher knowledge, which has been referred to as Pedagogical Content Knowledge (PCK), and Technological Pedagogical Content Knowledge (TPCK). This implies that teachers have the ability to apply technology into their pedagogical strategies and content representations for teaching specific topics to promote students' learning efficiency. This book discusses four studies related to PCK research and development and also four studies related to TPACK research, development and applications. The principal audiences for this book include all level school teachers, graduate students, academic researchers, and college teachers and scholars.