Engineering design is a knowledge-intensive process driven by various design objectives. Design is an iterative process where the objectives evolve together with the solutions in order to deliver an artefact with the desired properties and functions. Many design theories developed so far suggest more or less efficient ways for finding a suitable solution to the given goals. However, they often leave open the issue of ‘solution talkback’. Discovery of new design objectives and amendment of the existing ones is as important as the development of design solutions. The biggest issue with solution talkback is the presence of tacit knowledge in addition to the explicit one. This paper draws on a theory that incorporates some typical features of design problems, and transfers theoretical findings about reflection on the design actions to a tool for acquisition of design knowledge. First, key terms are defined and theoretical framework is introduced. Afterwards we look at the means for capturing explicit and tacit design knowledge more in depth.