How much can a handful of students - a few hundred Americans and Canadians each year do to reduce the great ignorance Africans and North Americans have of one another's social, economic and political customs? Some years before the inception of the Peace Corps, the Rev. James A. Robinson, a Hariem minister, set out to prove that such students could accomplish a great deal that would be meaningful. Dr. Robinson's great leadership qualities sprang, in part, from having identified in his own life the proper role of an African heritage for an American, an he apparently has been able to provide the Negroes who take part in Operation Crossroads Africa with much the same outlook. Crossroads makes it possible for undergraduates who supply roughly half their own expenses to spend a summer in small groups in one of several locations in East or West Africa, performing specific work projects (building a school, clinic, irrigation system, or similar physical labor). Africans in each local area are encouraged to participate, and the two groups usually live and work side by side with the informality and benefits of shared endeavor. Mrs. Plimpton has toured representative sites, and her report is a lively one. In addition to her own observations on the greater flexibility of a small-scale private effort over some vast, elaborate government aid program, she quotes from letters and journals of Crossroaders to whom the very personal nature of the scheme is its greatest asset. Ambassador Adlai Stevenson's preface underscores the way in which Operation Crossroads Africa dovetails into America's foreign policy goals.