Semiotics defined: 

1. studies signs relating to natural languages as well as other cultural sign systems; 
2. Systems of signification can be understood and elaborated upon through metalinguistic operations, that is, through access to secondary level of discourse . . .  
3. Systems of signification encompass denotative signs [and] connotative codes.

In short the universe of signs includes: the non-physiological part of perception; conception; scientific modes of discourse; and the value systems, or the socially constituted world views of social subjects, . . . " (2-3)

[different definitions]  Thus the issue framed by the articulated differences in approaches to semiotics in general becomes whether or not a unified perspective can be found to integrate at once all the social sciences and psychology, on the one hand, and logic and epistemology, on the other, by some general theory of semiotics -- and whether biology, ecology, and ethology can be included in the synthesis, . . . " (4)

  Two separate approaches  to urban semiotics: 

1. purely semiotic one and focuses on spatial systems [disregarding social context]; 
2. links such systems with their social contexts through the study of the ideology incorporated in them.  
Socio-semiotics, therefore, studies both systems of denotation and metalinguistic systems in relation to the culturally specific systems of connotation operating behind them. (5) 

Lynch['s environmental image of city]  ignored the connotaive level, 
There is little argument that the work of Lynch has led to a more human approach to urban design; one that explicitly recognizes the role of users in fathoming urban space.  Yet . . . 

• cognitive mapping research relies on a methodological individualism which accepts unquestioningly intra-subjective pictures of the environment as the basis of urban behavior.  Thus cognitive approaches arrive at the signification of the city through the perception of its inhabitants rather than their conception.  
• urban environment is reduced to a perceptual knowledge of physical form.  
• the famous five-fold distinction of paths, edges, nodes and so on, reduce the use of urban environments to activity of movement.  

--  has uncovered some important means by which inhabitants of the city organize their behavior.  Chief among these is the realization that conceptual stimuli in the environment play a more fundamental role than mere formal perscption, so that physical forms are assigned a certain significations which then aid in directing behavior.   Urban structures act as stimuli because they have become symbols and not because they support behavior by facilitating movement.   Thus we can say that the image of the city is a conceptual rather than perceptual one. 

[this is where socio-semiotics comes in.] 

3. [The editors' perspective] -- urban space is not a text but a "pseudo-text," because it is produced by non-semiotic processes as well as semiotic ones and because there is not always a sender in the historically conditioned built environment.  A socio-semiotic analysis of an urban sign system or "pseudo-text" would then procede as follows.  

• On the one hand, observational data would be collected on both the substance and form of the expression.  In the first case (substance), a description of material urban space invested by signifcation would be obtained, while in the second (form), attention would be given to the specific spatial elements which are the vehicles of signification.  
• On the other hand, cultural research is required to document the forms and substance of the content.  Such a task requires, firstly, attention to historically and culturally established signification, realized through research into the general cultural traits of the society within which the settlement space is embedded.  Secondly, considerable case study research is required to document the codified ideology structuring the signified of space.