Dynamic pointers: an abstraction for indicative manipulation

A discussion is on a formal model of interactive systems: dynamic pointers. This model is useful, not only as a formal description tool, but also as a key to the informal understanding of certain issues and as an implementation technique. The focus of the article is on manipulation by which is meant `doing things to things´. This is a rather wide definition, which at its simplest can be thought of as editing but at its richest encompasses virtually all interaction. The author goes on to discuss: modes of manipulation, mediated interaction, relating levels by translating pointers, changing objects with dynamic pointers and dynamic pointers for system integration