A study of the relationship between university-level second language development and previous language and other experience is described. The study, in its early stages at the time of writing, is being conducted at Trinity College in Dublin, Ireland, and involves students of French, German, Italian, and Spanish. This report describes the subjects and methodology, specific research questions addressed, research instruments and methods, computerization of the database, and some preliminary findings from small-scale studies. Early results concern the relationship between second language experience and second language proficiency, the development of second language lexicon, and the interaction between languages learned (interlanguage) and between language learning experiences. A 28-item bibliography is appended. (MSE)