At the first meeting of the project's advisory committee in January, 1990 the authors were advised to undertake a series of interviews. The authors agreed and embarked on an extensive interview program, ultimately talking with 149 persons. The interviews were conducted during the entire life of the project and included discussions with current and former Bank staff and executive directors, persons from related institutions such as the International Monetary Fund and the Asian Development Bank, and prominent external observers of the Bank. Some of the interviews were noted in footnotes in the published volumes of The World Bank: Its First Half Century. Series contains dupicate reference copies of almost all of the original interview tapes.

A series of interviews were conducted during a research trip the authors made to India, Bangladesh, Indonesia and the Philippines in November, 1991. These interviews were primarily with national leaders and focus particularly on the 1980s.

Some of the persons interviewed by the authors were also interviewed by the Bank's own oral history program; some also were interviewed by Robert Oliver for his biography of Bank president George D. Woods. The series also contains some of the transcripts from these older interviews.