This special issue offers a multidimensional perspective on the recent inquiries into knowledge representation. Multidimensionality exposes the complexity of knowledge representation and helps distinguish between different approaches and research tools. On the one hand, the presented research focuses on the theoretical and empirical aspects of knowledge representation (taking into account cognitive processes and capacities, including linguistic skills needed to generate and express knowledge); on the other, the articles included in the issue discuss the practical discourse, analyzing actions from the point (...) of view of cognitively oriented semantics and the scientific practice broadly understood. The issue consists of five papers that show how certain ideas in the research area of knowledge representation inspired the authors to look for new approaches to modelling concepts and practical reasoning, constructing theory of signs using the tools of data science, and dealing with cognitive artifacts in scientific practice and its dynamics. What these approaches have in common is their attempt at capturing the multidimensionality of knowledge representation in such a way that integrates them. Our goal is to emphasize some innovative aspects of those approaches with respect to the dynamics of knowledge representation in both the cognitive system and scientific practice. (shrink)