Several methods for evaluating the influence of antecedents on challenging behaviour have been described in the literature, however the portability of these methods within the classroom has been questionable. The purpose of this paper will be to provide a practical understanding of evidence-based practices used in the assessment and management of instructional antecedents. The importance of understanding the relationship between instructional antecedents and desired learner responses will be examined within the context of two adolescent learners with developmental disabilities who experienced challenging behaviour. (Contains 2 figures.)