The effects of e-mail feedback with written verbatim examples and frequency counts of expansions on pre-service teachers' verbal behaviors were examined in two studies. In Experiment I, e-mail feedback on the use of expansions was evaluated in a multiple baseline design across 3 undergraduate early childhood special education students. Results indicated a systematic relation between the e-mail feedback and the participant's use of expansions. Experiment II was a systematic replication of Experiment I. E-mail feedback on the use of expansions and specific praise was evaluated in a multiple baseline design across 3 student teachers. Results were similar to Experiment I. Student teachers' use of expansions displayed more variability than the practicum students. Implications for (a) the identification of effective practices for university supervisors, (b) the use of e-mail to communicate between supervisors and pre-service teachers, (c) future research on feedback, and (d) methods for conducting systematic replications are discussed. (Contains 6 figures and 5 tables.)