As part of their early research in nursery rhymes, the Opies had started in 1946 to write to the newspapers and magazines, such as The Sunday Times or The Times Literary Supplement, to ask readers to send rhymes and songs they remembered from their childhood.

When, after the completion of The Oxford Dictionary of Nursery Rhymes (1951), the Opies turned their attention to the lore and language of school children, they again wrote to The Sunday Times to seek help from readers in collecting “any accounts of skipping, ball bouncing, or counting-out rhymes, catch rhymes, riddle rhymes or tongue-twisters; also popular sayings, nominees, back chat, youthful oaths, and other joys, seemly or unseemly, traditional among schoolchildren from seven to fourteen.” ( The Sunday Times, 4 Nov 1951) Amongst the replies were many letters by teachers offering help, prompting the Opies to develop their first questionnaire ‘The Oral Lore of School Children’ in order to collect the accounts of childlore in a more systematic way, and directly from the children. This questionnaire evolved throughout the 1950s, and yielded thousands of individual replies.

Over the years, the Opies developed a large network of contacts from all over the UK. These contacts were usually teachers who would ask their pupils to answer the questionnaires. Each of the contacts was assigned an individual reference number by the Opies, linking to a series of address books which contain the correspondents contact details and information on their activity, when last contacted, which material received etc. (cf. MS. Opie 215). These reference numbers played a crucial role in keeping intellectual and physical control of the ever growing collection of research material.

After the completion of The Lore and Language of Schoolchildren in 1959, the Opies' research interest shifted from a focus on language and verbal traditions towards games and playground activities, which is also indicated by the use of a new questionnaire ('The Games and Crazes of Schoolchildren') from 1959/1960. This new questionnaire, used throughout the 1960s and early 1970s, produced a second large fund of children’s papers, which the Opies used as the raw material for their books on children’s games, in particular for Children’s Games in Street and Playground, published in 1969.

Many of the children’s papers are copied out or clipped, as the Opies used to excerpt descriptions of rhymes, games or activities of particular interest and add them into their subject-based working files. These files can now be found in series B. Working Papers.