Timing

The timing of an action can completely change its meaning. Therefore timing has become one of the most important principles of animation. The timing is altered by the number of in-betweens separating two extreme keyframe positions.

Say, for example, in the first keyframe a character has his right arm stretched to the left of his body and in the second keyframe his right arm is stretched to the right. If there were only two or three in-betweens, the character would appear to be swiping at a fly in front of him. If there were, say, twenty in-betweens, the character would appear to be pointing out the size of a distant mountain range or forest.