Categories derived from names for fauna and flora reported on the First Census of the Indigenous Communities of the Peruvian Amazon in 1993 are discussed. Sources of variance and ambiguities, decisions made to prepare coding categories for tabulation and statistical data, and methods used to reference local names for life forms to Latin binomial names are detailed. The words originating in respondents’ languages actually reported, the raw frequencies of reports for these terms, and their probable biological references are presented. Some alternative methods are recommended which may permit collection and processing of precise information by overcoming cultural and linguistic differences between local respondents and Western sciences.