Background: The provision of skilled support is dependent on staff knowledge and understanding (Beadle-Brown J., Beecham J., Mansell J., Baumker T., Leigh J., Whelton R. & Richardson L, unpublished data). Influencing staff knowledge and understanding is an important component of interventions. Materials and Methods: Fourteen individual semi-structured interviews elicited staff views and experiences of knowledge development. These were analysed using a thematic network analysis (Attride-Stirling 2001, "Qualitative Research" 1, 385-405). Results: Three global themes were identified; "skills are developed from experience, service aims influence service delivery and practice is more important than theory." This article focuses on the first of these themes. Relationships between staff and service users played a central role in enabling development of knowledge. Although some skills were seen as transferrable, experience of a particular service user was described as being essential. Conclusions: Support staff may not see the relevance of research findings, professional knowledge or training, unless these have involved direct work with the service user in question. (Contains 1 table, 1 figure, and 1 footnote.)