This paper treats methodological issues involved in assessing linguistic competence in the field, specifically in bilingual fieldwork situations. First, the various means of assessment of linguistic competence that have been described and/or used are listed and commented on. Then the authors explain the choice of assessment methods for fieldwork in the Slovene minority region of Austria: among other fieldwork tests, self-assessments of two different kinds (more general and situation-specific self-assessments) were combined with third-party assessments of taped storytelling. The specific fieldwork methodology and assessment methods are described. The results that bear on methodology suggest that self-assessments of linguistic competence are unreliable; that fieldworkers should pay attention to the kind of linguistic competence they wish to characterise; and, when storytelling proficiency testing is used, that different types of storytelling tasks should be employed. (Contains 7 tables and 8 notes.)