If performance management is the task of getting the public-works crews to fill the potholes promptly, efficiently, and effectively, it is important (and not always easy) task. Yet, this kind of level-one performance-management problem is not all that complex. And, although not every governmental jurisdiction or public agency has mastered all such straightforward level-one performance problems, those that have now face more complex challenges—level-two or even level-four challenges. For example, some organizations have to figure out how to collaborate for performance. In such circumstances, neither the allocation of responsibilities nor the nature of the accountability structure are clear. Instead, the collaborators in such “hybrid organizations” have to figure out how to divide responsibilities among organizations and people. And they have to design—indeed, experiment with—new accountability relationships. They have to create a new governance structures that are unique to the nature of their collective purposes and to the character of their individual organizations. Some organizations have to figure out how to move from after-the-fact reaction to anticipatory action. Much of the practice and research on performance management has focused on reducing crime. Indeed, with the spread of CompStat from New York to other police departments across the world—and, to other kinds of public agencies and even entire jurisdictions—this performance strategy has proven effective. Yet for such pervasive public problems as crime, child welfare, and homelessness, the real management challenge is to prevent the problem from ever occurring. Such preventive strategies often require collaboration. Unfortunately, for neither collaboration nor prevention, can effective strategies be codified in formulas or blueprints or instruction manuals. For the knowledge about performance management is primarily tacit—rarely explicit. Consequently, neither practitioners nor scholars can present their knowledge in ways that permit direct deployment in new circumstances. For although their tacit knowledge may be extremely valuable, it primarily a collection of leadership principles that public managers must adapt when they seek to employ these principles in new circumstances. Throughout all these next-level challenges, one challenge remains fundamental: What to measure, how to measure it, and how to use the measures? Performance management depends on performance measurement. Yet the most useful measures—near-term, outcome measures—are rarely available. When it is possible to measure outcomes, it is often only years or decades later. And even if such sometime-in-the-future outcomes could be measured, they are of little use to today’s managers (even if the attribution problem could be solved). And one of the ways that performance measures could prove useful is the allocation of resources. Yet, even budgeting for performance is not a simple, straight-forward process—particularly if the purpose for which the resources are to be allocated requires collaboration among those competing for budgetary resources. Such next-level performance-management challenges will necessarily be tackled through experimentation. The papers on this panel suggest how both practitioners and scholars are thinking about and engaging in these experiments.