[Co-production of knowledge about custody criteria with subjects affected by their parents' custody dispute: a participatory study].

This article explores methods within a longitudinal study for allowing subjects more direct participation in research as co-producers of scientific knowledge concerning custody decision-making after divorce. The purpose of the longitudinal study was to evaluate the scientific custody criteria that were applied to children after their parents' divorce. The results of the study, published after the first survey, showed the relevance of children's personal preferences and residence wishes for custody regulations. This was formulated as a general rule for custody decision-making. In the second survey, a copy of our scientific publication written after the first survey, including summaries and a questionnaire was sent to the children involved. They were asked to judge the presentation of the custody problem, the custody recommendations and the presentation of their case history in our publication. Most of the participants (60%) voted for the application of the custody criterion "personal relationship preferences and residence wishes", but they also pointed out the difficulties for the child to articulate those wishes. Together with other studies, the participatory study contributed to a paradigm shift: from an understanding of the custody problem as a structural question concerning the suitability of maternal, paternal or joint custody to a conceptualisation of the custody problem as a decision-making process that demands the participation of the child and professional support if need be. Finally, the value of participatory research methods in divorce research and longitudinal social studies of children and childhood are discussed.