Book excerpt: Effective practitioners in any field understand that lessons from the past underlie successes in the future. Which practices have worked before and which haven’t? What went wrong, and what does that teach us? Too often, however, urban and regional planners simply don’t know whether or how well planning policies were carried out. Evaluating Urban and Regional Plans blends theory and practice to delineate the questions that planners need to ask as they shape the future of Canadian communities. Mark Seasons offers a wealth of pragmatic guidance on comprehensive plan evaluation processes and methods. Monitoring the outputs and outcomes generated by a plan – and gauging their impact – ensures that the planning function remains relevant, and that resources are used effectively, efficiently, and equitably. As both a primer on plan evaluation practice and an original contribution to theory, Evaluating Urban and Regional Plans is an invaluable resource not only for the Canadian planning community but for planners everywhere.