In this article, we present unselfconscious interaction, a conceptual construct that describes a form of interaction with computational artifacts animated by incremental intersections that lead to improvements in the relationships among artifacts, environments and people. We draw on Christopher Alexander's notion of goodness of fit and unselfconscious culture, and utilize Erik Stolterman and Mikael Wiberg's concept-driven interaction research to analyze three interaction design concept artifacts to develop the construct of unselfconscious interaction for human–computer interaction. The resulting construct is comprised of the motivation of goodness of fit that is supported by two design qualities we name open-endedness and lived-with. We describe tensions within the construct, the notion of purposeful purposelessness in design and discuss the features that derive from Alexander's unselfconscious culture and are to be considered when designing for goodness of fit: resources, adaptation, ensembles, time and anonymity. Our main contribution in this article lies in the articulation of the construct of unselfconscious interaction.