John Mason grew up in Canada where he received his BSc and MSc in mathematics. He then went to Madison Wisconsin for a PhD, and it was there that he encountered the film Let Us Teach Guessing featuring George Pólya. Inspired, John changed his teaching overnight, developing an interactive style in alignment with the film and with the way his high school teacher had taught him. He then joined the Open University Mathematics Department, where he designed two of the mathematics summer schools, contributed to numerous courses, and then helped form and run the Centre for Mathematics Education.
He has written numerous books and booklets, as well as research articles and book chapters, some by himself and some with colleagues. Perhaps best known is Thinking Mathematically with Leone Burton & Kaye Stacey, written in 1982, and which appeared in an extended edition in 2010. His approach to research is outlined in Researching Your Own Practice: the discipline of noticing, based on the way of working he and his colleagues developed at the Open University, and itself based on psychological insights from the middle and far east. John and his wife Anne Watson collaborated on Mathematics as a Constructive Enterprise: learners generating examples and several related papers, and on Questions and Prompts for Mathematical Thinking which is used internationally.
John retired from the Open University in 2009 but continues to think about mathematical problems, to work on pedagogical issues, and to construct applets to assist him in workshops.