Abstract
The relationship between two notions, "legibility" proposed by Lynch and "ambiguity" proposed by Rapoport, is studied in the following three levels using the information theory. (1) Key elements which were discussed in part 1 could be considered to have the higher recalling probabilities (<1/8) because they contained the higher amount of information. If the higher amount of information of key elements could mean the higher "ambiguity" of them, this higher "ambiguity" of key elements must be acting to give the higher "legibility" of the district they belong to. This assumption should be extended to the higher level that the "legibility" of an entire city must be constructed by the higher "ambiguity" of certain key districts. (2) The coexistancy of these 2 notions in the same level of district is discussed here. General increasing tendency of entropies of the recalling probability distribution along the sequence of recalling stages is considered to mean that the concentration to certain key elements is more evident in the earlier stage and the dissolution into more personal elements in the later stage of the recalling process of the interviewees. From this observation the better coexistance of "legibility" and "ambiguity" could be assumed to be where the increasing ratio of entropy is higher. (3) If the gradual increase of entropy (ambiguity) is assumed to be in the naturally maturing process of districts, the district planning is considered as the abrupt decreasing process of entropy in order to realize higher "legibility" without sacrifizing "ambiguity" of the district by the intentional reorganization of the image distribution.
