Each Guide/Girl Scout defines her own progress and development according to her needs and aspirations within the framework program provided. This contrasts with many formal education systems where young people must fit themselves into a rigid structure with little recognition of individual needs and differences. The Girl Guide/Girl Scout method is the specific way that the leadership works with girls and young women to achieve the mission of WAGGGS. It is an integrated approach with certain key elements: The Girl Guiding/Girl Scouting method can be used equally effectively with girls of all ages, abilities and backgrounds. In his book "Girl Guiding," Lord Baden-Powell (1918) wrote: