In 1998, I built and led a small company that has helped school and district leaders make sense of their vital signs, and communicate them to others. In serving 240+ California districts, I learned a lot about the hazards of interpreting accountability status and students' test scores. Witnessing two decades of mistakes, errors, and misjudgments led me to appreciate the learning opportunities these moments afforded. Now I lead a team, the K12 Measures group, part of School Wise Press, that's bringing analytic support to education leaders. The book, "Mismeasuring Schools' Vital Signs," combines those stories into object lessons that my co-author and I believe can help advance the quality of human judgment that education leaders bring to their day-to-day work.