Abstract
Constructive assemblies are tangible user interfaces (TUIs) that involve the interconnection of modular parts. As such, they offer a unique means to support us in our various and diverse activities. However, little information is available for understanding the intricacies of taking a modular, constructive assembly approach to TUI design. Based on an analysis of extensive data collected from interviews with eight world-class TUI experts, we propose a descriptive, conceptual framework to facilitate systematic investigation and critical consideration of constructive assemblies. The paper presents a lifecycle model for constructive assemblies and discusses their main design qualities and associated parameters. We demonstrate how this can be used to structure critical discussions by applying the principles to existing works and the design of our own constructive assembly.