Endoparasite (internal parasites) management is an important aspect of pastoral livestock farming. It involves understanding some complex biological principles and making decisions in a farm systems context. In New Zealand there is some confusion and diverse messages presented about endoparasites making it difficult for the farming industry to derive “best practice”. A programme to improve the consistency of information provided to farmers about endoparasites was established. This paper focuses on a suite of methodologies for studying regional differences in farmers perceptions and management needs with respect to endoparasites. This understanding was used to design new decision tools to assist farmers. This paper will discuss the way the methodology set the foundation and strategy for the overall technology development of the research team and suggest possible extensions to similar national programmes. Farmer focus groups were held in 9 selected regions. Each group performed several tasks, viz.: Cognitive mapping had farmers interactively constructing their views on the general management, regional issues, and information gaps involved in parasite management. Surveying the types of information and key people farmers use to make decisions. A paired comparison of key concepts in parasite management was included in the survey to compare across regions. Transcript analysis of group meetings enabled an analysis of farmers’ reasoning that underpinned the construction of their cognitive maps. Development of a regional information network was achieved by asking farmers for other contacts who they consider have a keen interest in the topic and working interactively with these contacts when trialling new decision aids. The relevance of this methodology to study information needs for other complex systems is discussed.