This study, colloquially known as '100 Families', sought to trace connections between family life and social mobility. It did so through 170 in-depth life story interviews spread across three generations of family life. The research team, headed by Paul Thompson and Howard Newby at the University of Essex, devised an interview schedule that asked participants extensive questions relating to their own and their family's education, politics, family trees, marriage and relationships, housing, parents' work, and leisure. The interviews average 54 pages in length and were conducted during the mid-1980s. The fieldwork strategy selected a 'middle generation' of married men and women with children. These 'middle generation' informants were initially drawn from a subsample of informants interviewed for an ESRC project and had agreed to be re-interviewed. They were located in 200 polling districts in 35 parliamentary constituencies in Scotland, London, north-west, west and south-east England and the Midlands. Later on, further polling districts were added and a stratified occupational quota was introduced to ensure an appropriate class balance. The collection consists of interviews with 170 respondents; 87 middle-generation, 42 younger, and 41 older. The families included 26 represented by a lone participant and 11 where all three generations were interviewed. The survey was carried out with the purpose of gathering ethnographic and dynamic information illustrative of family, ageing, and social mobility. The semi-structured interview transcripts combine accounts of family background and occupations with full life stories covering education, politics, family tree, marriage and relationships, housing, parents' work, and leisure.