Beyond Applications: Interaction Substrates and Instruments

Abstract

This paper introduces a new interaction model based on the concepts of interaction substrate for organizing digital information and interaction instruments for manipulating these substrates. This approach makes the concept of application unnecessary. Instead, it leads to flexible and extensible environments in which users can combine content at will and choose the tools they need to manipulate it. We present Stratify, a proof-of-concept implementation that combines a data-reactive approach to specify relationships among digital objects with a functional-reactive approach to handle interaction. This combination enables the creation of rich information substrates that can be freely inspected and modified, as well as interaction instruments that are decoupled from the objects they interact with, making it possible to use instruments with objects they were not designed for. We illustrate the flexibility of the approach with several examples and present directions for future work.