Barriers are defined as discontinuties in the broadly defined marginal costs of communications, usually leading to a discontinuity in interaction. This paper addresses conceptual issues about barriers to communication. Several typologies of barriers are given. For example, according to the...

The advent of telecommunications and the emergence of the 'information age` have given rise to great expectations regarding urban change. The paper examines the assumptions underlying the claims for change and distinguishes between processes which may alter the structure of the city and those...