Disclosed is an automated system, machine-readable storage medium embodying computer-executable code, and method for generating descriptive words and optionally, multi-word groups derived from a digitally encoded, natural-language input text that describes a concept, invention, or event in a selected field. The system includes (a) an electronic digital computer, (b) a database of words and optionally, word-groups derived from a plurality of texts, and (c) machine-readable storage medium embodying computer-executable code for accessing the database. The database provides, or can be used to calculate, a selectivity value for each of the words and optionally, word groups contained in or derived from the input text. Words and optionally, word groups having an above-threshold selectivity value are selected as descriptive terms from the input text.