ABSTRACT
As with theoretical linguistic research, a primary data source for Universal Grammar (UG)-based studies of second-language acquisition (SLA) is often found in learners’ assessments of the grammaticality status of sentences in the target language. 1 Some researchers, however, have questioned whether judgmental evidence should be accorded the same ontological status in L2 research that it enjoys in theoretical research (e.g., Christie & Lantolf, 1992; Ellis, 1990, 1991; Sorace, 1988). 2 Fundamentally, the issue is to determine the basis on which L2 learners render judgments of test sentences. Do learners access abstract grammatical knowledge or do they rely on some other knowledge source, such as memory of what someone (e.g., a language teacher) has told them, memory of what they think someone has told them, their own folk knowledge, or L1 equivalents, when carrying out such tasks? Until the validity issue is resolved, it will be difficult to have confidence in the claims of L2 research predicated on judgment data. This chapter is intended as a contribution to the resolution of this problem.
