Video is a powerful tool to use in the assessment of practical work. For the Demonstration type of practical, the student is exposed to an experiment performed by the teacher or other experts recorded previously and made available to students as a single file or integrated in a structured learning object, complemented with other types of content, including online tests. The great advantage is that this type of file may be reused. Also, with the help of a video expert is possible to use techniques to highlight parts of the procedure that are more important or difficult.
For the other types of practicals described above, video files may be produced by students to demonstrate their performance that can then be assessed by the teacher or their peers. It is a powerful tool for self assessment because it allows the student to review his own performance.
Some types of phenomena or procedures may be difficult to capture in video. In these cases, the teacher may produce an animation to demonstrate a procedure. It requires technical skills to develop but it has great reuse potential
An alternative to video for demonstration purposes or assessment of skills is using a sequence of images. It has the advantage of being easier to produce than video.