This paper looks at the impact, use and design of tutorial videos for two cohorts of senior undergraduate electrical engineering students. The videos are designed to augment in-person lectures and tutorials. This allows more problems to be covered or previously covered problems to be revised. We investigate how the videos impact student performance, whether students attempt problems before, during or after the videos and how students use the videos. We find that students use the tutorial videos in a variety of ways, including some that were unexpected. Results show wide spread use of the tutorial videos and indicate that students customised their learning environment to suit their needs, using both in-person and online resources. The value of tutorial videos on difficult concepts and troublesome knowledge is particularly clear. This highlights the importance of providing additional resources for such concepts and knowledge in order to improve student achievement. Different video design approaches and suggestions for further enhancements are also presented.