I would strongly discourage the use of video as a substitute for a teacher. However, I do agree that short videos can be an effective teaching aide to support learning in certain areas.
These topics are typically areas where you can’t get out and see the real thing; for example, space or the ocean. Videos are for immediate learning. I would encourage that parents be involved with possible follow-ups. For example, in these cases it could be a family outing to the beach or looking at the night sky.
As early childhood educators we have the ability to use videos as a mechanism for following up on specific children’s questions or interests. They are a tool for information gathering for areas of interest to the children at that particular time. For example, where the children saw something quickly in the garden and want to learn more.
Video can be an excellent way to introduce the children to technology and the concept of youtube and video on demand.
Examples of areas where video is a useful teaching aide:
Styles of transport (e.g. types of trucks (recycling trucks, street sweepers), trains)
Let me know what videos you have found useful as an immediate learning aid for me to add to this list.