Improving access to education for girls requires that the incentives structures for families be changed, and that social and cultural norms that lead parents to interrupt the schooling of girls earlier than that of boys be challenged. Many poor households are unable to send girls to school because of the costs, both direct and indirect (school fees or other costs related to attending school, such as uniforms and books), of doing so; because of opportunity costs (girls who go to school are not available to work within the household); because of the commute involved, when the family lives at a far distance from the nearest school, and associated security concerns. The absence of separate sanitation facilities for girls in schools can also be a major obstacle.