Data that can be used to inform policy decisions are typically scarce in low-income countries, where standard policy prescriptions are less likely to apply. Interventions based on inadequate information and thus misguided assumptions may not achieve expected results, despite the fact that substantial public or donor funds are being spent. For example, an adjustment operation that focuses on spending allocations may achieve its benchmarks but have no effect on actual service delivery. Diagnostic surveys can provide vital information for decision-makers when institutional weaknesses inhibit a more regular flow of information. If strategically designed, a survey can help induce policy change by pointing directly to the main bottlenecks, making it easier for policymakers to find solutions. This note summarizes a case in Uganda where a diagnostic survey proved particularly useful in an effort to improve public spending on health and education.