Introducing cross-theoretical explorations of interlocutors and their individual differences / Laura Gurzynski-Weiss -- On the role of the interlocutor in second language development : a cognitive-interactionist approach / Jenefer Philp and Laura Gurzynski-Weiss -- The effect of proficiency, gender, and learning style on the occurrence of negotiated interaction in communicative task performance / Miroslaw Pawlak -- I~You>& I~Me : the hidden other in L2 development / James P. Lantolf -- Interlocutor differences and the role of social others in a Spanish peer tutoring context / Michele Back -- Variationist perspective(s) on interlocutor individual differences / Kimberly L. Geeslin -- Examining the role of instructor first language in classroom-based oral input / Avizia Yim Long and Kimberly L. Geeslin -- Complexity theory : relational systems in interaction and in interlocutor differences in second language development / Diane Larsen-Freeman -- The impact of learner perceptions of interlocutor individual differences on learner possible selves during a short-term experience abroad / Ellen Johnson Serafini -- Synthesizing cross-theoretical explorations of interlocutors and their individual differences / Laura Gurzynski-Weiss.