 The last but not least relevant factor is that BLS requires transferring the skill into an unpracticed context 13. While orthopedic surgery is learned and performed in fairly comparable and repeatable conditions, BLS is learned in a classroom but needs to be transferred wherever a cardiac arrest takes place. Because contextual interference not only favours better retention but also better transfer to new situations 20, it is imperative to test if such a practice can lead to better BLS skill retention and transferability than conventional blocked practice schedules. 