Sociologist Erving Goffman wrote about 'expressive equipment', the things "intentionally or unwittingly employed by the individual during their performance*". As a designer, I am interested in the design of these 'things' and the power they hold in aiding an individual to explore and perform ideas, thoughts, feelings they weren't initially consciously aware of.
I intend to borrow and adapt this idea of 'expressive equipment' into that of 'expressive artifacts.' The primary difference being the scale at which these expressive tools exist. While the word equipment suggests structures to move through or position yourself on—a sort of experiential architecture—the word artifact is drawn from the language of product design to imply a smaller-than-human scale.
*Goffman defines performance as "all the activity of an individual which occurs during a period marked by his continuous presence before a particular set of observers and which has some influence on the observers."