 The proposed study will compare skill retention among a group of laypeople being taught BLS using the current standard teaching program compared to those exposed to a CI based program. We hypothesize that participants trained in BLS using a contextual interference practice schedule will have superior skill retention at a retention post-test, 3 months after training, compared to the standard blocked practice schedule employed in current BLS training sessions. This study will be a single-blinded randomized controlled trial. Ethical approval will be obtained from the Ottawa Health Science Research Ethics Board prior to recruitment. Written informed consent and a confidentiality agreement will be obtained from all participants. 