This chapter examines data-driven learner personas and instructional scaffolding in the form of preemptive feedback in an ICALL environment. Ninety-three beginner learners of L2 German participated in a study by performing a sentence completion task as part of their regular course assignments throughout a semester. On the basis of their access to help throughout the study, participants were classified into three distinctive learner profiles, or personas: No Help, Sporadic Help, and Frequent Help personas. The study then investigated the effects of access to different amounts of help on the learners’ working behaviour and linguistic performance. Study results indicate that the three learner personas showed significant differences in their working behaviour and linguistic performance, but by investigating the effects of the instructional scaffolding the CALL system provided, results suggest that two learner personas are sufficient to capture learners’ differences. With the ultimate goal of understanding learner personas and instructional scaffolding as it relates to learning outcomes, satisfaction and success in CALL, this paper provides possible explanations of these study results and suggests areas for future research and development.