Knowledge visualisation is enjoying increasing attention from researchers and organisations, due to its potential for expediting knowledge transfer. Despite the availability of many information visualisation guidelines, those who are tasked to produce knowledge visualisations currently do so without any formal guidance. These unguided efforts do not reliably deliver efficacious visualisations. The research reported in this paper sought first to delineate the essence of knowledge visualisation. We captured this essence in the form of a comprehensive definition as well as a list of essential criteria exhibited by effective knowledge visualisations. Using these, we moved on to address the lack of guidance by producing a set of knowledge visualisation guidelines. We report on how we derived and evaluated these guidelines. The guidelines, despite the rigorous derivation process, did not help the evaluators to produce effective visualisations. We reflect on the reasons for this and report on a number of lessons learned during the process. We conclude by suggesting a direction for future research. CCS CONCEPTS • Human-centered computing → Visualization theory, concepts and paradigms; Visualization design and evaluation methods; Empirical studies in visualization;