This doctoral research set out to understand the impact of a video annotation-embedded in instructional scenarios on the professional development of VET students. Under the hypothesis that the implementation of video annotation-supported environment can foster reflection-on-action, collective and individual feedback and discussion, as well as knowledge co-construction through the collaborative design of learning artefacts, we designed two experimental scenario to test whether video annotation positively impact students’ learning gains acquisition and professional development. Informed by a state-of-the-art literature review on video annotation (Study 1), such impact has been explored in terms of learners’ knowledge acquisition (Study 2), and of learners’ reflective skills which in turn can lead to the betterment of professional practice (Study 3). Our thesis’ objective is hence two-folded: on the one hand we aim at gathering evidence-driven data to test our video annotation efficacy-related hypothesis and research questions. On the other hand, we also intend to provide instructional designers with the recommendations needed to embed their educational and training scenarios with video annotation and video authoring tools. Findings supports theoretical assumptions on the value of video annotation for learning gains acquisition and professional development aims, provide useful information to instructors willing to adopt collaborative use of interactive video tools, and shed light on the value of video annotation-supported instructional scenarios in authentic VET settings.