A serious book written by a well-known mathematics education researcher. I reaped multiple benefits from reading this book: First, it provides well-drawn picture about what factors influence the process and outcome of people's problem solving. And how these factors intertwine together. Second, it serves as a perfect example of digging information from messy data. The latter is especially valuable for novice researchers. Last, it makes me understand that math literature can also be presented in a humorous tone.
One of the very few books on problem solving (especially for mathematics). Learn't a lot from the first half of the book which provides the theoretical grounding/framework on improving problem solving. I have been wanting to practice solving historical math olympiad problems and this guide will be invaluable for it. It even has a chapter on Heuristics inspired by Polya's How to Solve It.
Interesting experiment in how individuals (from students to math professors) use heuristics to solve problems. Taught me a lot about how people handicap themselves and changed how I approach many new problems. I always wished there was further material by Schoenfeld on this topic.