This book examines the various areas of mathematics education and neighboring disciplines that have recently contributed to a better understanding of the still vague construct of diagnostic competence. The work addresses the nature, development and effect of diagnostic competence in mathematics instruction, with a focus on the professional development of teachers.

Timo Leuders is professor of mathematics education and vice president for research at the University of Education Freiburg, Germany. His research interests comprise the psychology of teaching and learning of mathematics at secondary level and pre-service and in-service teacher education.Juliane Leuders is a lecturer at the Institute of Mathematics education at the University of Education Freiburg, Germany. She earned a doctoral degree at the Faculty of Rehabilitation sciences at TU Dortmund University. In research and teaching, she focusses on inclusive education, mathematics education, and early childhood education. Kathleen Philipp is professor for teaching and learning of mathematics at the University of Applied Sciences and Arts of Northwestern Switzerland, School of Education. The focus of her research is on mathematical thinking of students and on competences of mathematics teachers at primary level.