It and bit. Nessi fra alcune teorie dell'informazione, della conoscenza, del documento e della realtà

The different senses of the term 'information' in physical, biological and social interpretations, and the possibility of connections between them, are addressed. Special attention is paid to Hofkirchner's unified theory of information (UTI), proposing an integrated view in which the notion of information gets additional properties as one moves from the physical to the biological and the social realms. In the paper UTI is compared to other views of information, especially to two theories complementing several ideas of it: the hypertextual docuverse theory (HDT) and the integrative levels theory (ILT). Two alternative applications of the complex of these three theories are discussed: a pragmatical, hermeneutic one, and a more ambitious realist, ontological one. The latter can be extended until considering information ('bit') together with matter-energy ('it') as a fundamental element in the world.