The report details the Irish portion of an experiment in tandem language learning by electronic mail (e-mail). The partners were Trinity College, Dublin (Ireland) and Ruhr University, Bochum (Germany), funded by the European Union within the International E-Mail Tandem Network as part of a two-year project. Tandem language learning is a form of open learning in which two individuals with different native languages work together to learn each other's language, in this case, English and German; success depends on adherence to the principles of reciprocity and learner autonomy. The report describes the network and the principles of tandem language learning by e-mail, the organization of this part of the study, including pedagogical design and considerations, the process of affective and linguistic data collection, and data analysis. The linguistic data analysis focused on bilingual skills, language register, discourse fillers, punctuation, explicit coordination between partners, error correction and generalizations made, thematic content, control and critical detachment, use of metalanguage, and accuracy of corrections. Implications for future work in this area are discussed briefly. Contains 10 references. (MSE)