A method of and apparatus for applying a parametric search methodology to a searchable database formatted in a directory tree structure. The directory tree structure includes nodes comprising a collection of related data and branches comprising links between the nodes. Each specific node provides a corresponding set of parameters by which each related item of data corresponding to the specific node is defined by initializing the value of each parameter for each related data. The method accesses a particular node within the directory tree structure and performs a parametric search using one or more set search parameters corresponding to the specific node to generate one or more matching discrete data items, wherein each matching item corresponds to related data of the particular node. The parameters can be customizable and specific to the specific node. The method can also include accessing a particular node utilizing a selective one or more search methodologies including keyword search, hierarchical search, and dichotomous key search.