During the COVID-19 pandemic, it became evident that the effectiveness of applying intervention measures is significantly influenced by societal acceptance, which, in turn, is affected by the processes of opinion formation. This article explores one among the many possibilities of coupled opinion–epidemic systems. The findings reveal either intricate periodic patterns or chaotic dynamics, leading to substantial fluctuations in opinion distribution and, consequently, significant variations in the total number of infections over time. Interestingly, the model exhibits a protective pattern.

The paper proposes a new visualisation in the form of vectors of not-fully-known quantitative features. The proposal is put in the context of project defining and planning and the importance of visualisation for decision making. The new approach is empirically compared with the already known visualisation utilizing membership functions of triangular fuzzy numbers. The designed and conducted experiment was aimed at evaluating the usability of the new approach according to ISO 9241–11. Overall 76 subjects performed 72 experimental conditions designed to assess the effectiveness of uncertainty conveyance. Efficiency and satisfaction were examined by participants subjective assessment of appropriate statements. The experiment results show that the proposed visualisation may constitute a significant alternative to the known, triangle-based visualisation. The paper emphasizes potential advantages for the proposed representation for project management and in other areas.