The video consumption tends to grow in coming years and it will be increasingly imperative to know the validity and effectiveness of using this type of media especially in teach and learn activities. It is very important to be able to assess how much knowledge a particular didactic video content was effective in building students knowledge. In this paper we present a tool we developed and an experiment we realized with two classes of computer engineering course related to network computer subjects, totalizing 140 students. In our experiment we divided our students in two groups: half of them attended a video explanation and half of them had the same explanation but only in a traditional classroom format. Our experiments show that video can be a great ally in the teaching and learning processes. Nevertheless, our investigation must continue in order to understand all video potential in this purpose.