Here is a link to a video that I posted last year. It remains a good one for the young scientist.
There are many videos of the scientific method that you might find interesting. Check YouTube: Scientific Method and you’ll probably find multiple songs, cartoons, videos and lectures for the family to enjoy. One in particular that I came across was the BrainPOP video of the scientific method. Your kids will stay with this video long enough that the scientific method might have a chance to take root.