Stop motion animation

Ray Harryhausen was one of the pioneers of stop motion animation. His works include
Mighty Joe Young (1949), The 7th Voyage of Sinbad (1958), Jason and the Argonauts (1963), and Clash of the Titans (1981). His technique involved animating on top of filmed footage using a technique he coined as Dynamation.

Phil Tippet

Go motion is fundamentally different to stop motion because of the shots being taken with a motion blur. While traditional stop motion featured static posed models, Go motion features rigged characters that would move while the shot was exposed, giving the image a motion blur that overall made the animations less jerky like many of the stop motion films were. 

Dynamation allowed for the combination of live action footage with stop motion animation. First the scenes would be rehearsed and shot, then using a projector and smaller stop motion set, Harryhausen would impose the figures in front of the screen, then re record the film with both the original footage and the new stop motion footage.