A Note on Local Ultrametricity in Text

Structures that are inherent to data of any type can be of import ance, and hierarchical structure is a prime example. In this work we take text corpora and assess the extent of hierarchical structure among words co nstituting the texts. By comprehensively taking context into account we seek to study hierarchical structures in the domain semantics. The data studied in Rammal et al. (1986) and Murtagh (2004) is point pattern data: observational features with their measurements on many coordinate dimensions. Data may be instead presented as time-varyin g signals and in a similar way, related to the findings of Rammal et al. (1986) and 1 Murtagh (2004), we have investigated ultrametric-related prope rties of time series or 1D signals in Murtagh (2005a).