As international agencies' assistance strategies become more complex, their methods of planning and administration become less effective. Neither the rationalistic techniques of planning and management they adopted during the 1960s and 1970s to control development activities nor the structural adjustment models they used during the 1980s and 1990s to reform economic policies, encouraged the flexibility, experimentation and social learning that are crucial to implementing successfully complex and uncertain development activities. Urgent reorientation of development programmes and continuous...