Over the years, students, graduates and colleagues have participated in the survey campaigns, organised and directed by UAM Professor
Inés Fernández-Ordóñez, sometimes repeatedly. All of them, after prior training to ensure a certain methodological unity, have contributed to enriching this corpus and, therefore, are as much a part of COSER (and of its successes and limitations) as the informants we interviewed. Starting with a first practice field trip to the mountains of León the spring of 1988, which served as an experiment, regular campaigns began to take place from 1989-1990 academic year, each one focused, in general, on carrying out interviews in a geographical area. The size of the area covered is generally proportional to the number of participants in the campaign and its duration. We list below the campaigns, the participants and the photographic memories we keep.