A method of and apparatus for performing a research task interchangeably utilizes a multitude of search methodologies including keyword search, hierarchical search, dichotomous key search, and parametric search. A search criteria is correlated to a searchable database for generating one or more matching items, wherein each matching item corresponds to a segment of the searchable database. The process is repeated by correlating a subsequent search criteria to one of the matching items for generating one or more subsequent matching items until the research task is completed. The searchable database can be formatted in a directory tree structure which includes nodes comprising a collection of related data and branches comprising links between the nodes. The collection of related data for a particular node can be displayed in an encyclopedia-like format. A specific node within the directory tree structure is accessible using a query string which defines a navigation path through the directory tree structure to access the specific node.