Walt Disney and his team of animators created the 12 Principals of Animation in the 1930's, and were created to try and convey the life and personality of the characters. Before the 12 Principals of animation, there were good animations and they were created not only to improve on Disney's Animations but to help explain what the animators were trying to show.
1.Squash and Stretch
This is the first principal which looks at the material of the object. The main example used is a ball bouncing, example is if the ball stretches as it falls and then squashes out once it hits the floor then its material is closer to something like rubber while if there is no squash or stretch the ball is more solid like ceramic or steel.
2.Anticipation
This covers the expectations that come about from the audience in response to what there expectations of what will happen in the animation. Example being a character will do an action in preparation for another action.
3.Staging
This is the presentation of an idea and is the part which is communicated to the audience. It should communicate the character/objects mood, attitude or stance in the story's current situation. Staging also directs the audiences attention through the use of camera angles and the character being the main focal point and not being up staged.
4.Straight ahead and Pose to Pose
These are two styles of working in animation both with pros and cons. Straight ahead is as it says, straight into it animation which means drawing out the animation frame by frame, while it gives the animation more fluidity and it allows for more freedom of the direction you want to take the animation, however it can result in warped and inconsistent sized animation. Pose to pose however works in a much more organised manner making use of key frames, which are key points in the animation and then the animation is tweened, (adding the frames in between the key frames). This method givens the animation process a time as there is a definite start and end, but it sets the animation in a scene with not much room for change.
5.Follow Through and Overlapping Action
Follow through is the termination of an action, or the end, while overlapping is what happens after the termination of one part of an action. An example would be a persons head, while a head moves back and forth the hair will follow after it and once that head stops the hair will swish back and continue on.
6.Slow-Out and Slow-In
This makes the animation seem more life like, everything starts with a gradual increase in speed and the action will stop with a gradual slow down. A standing pose doesn't immediately go into a high speed run, theres a gradual increase in speed until it reaches its terminal speed as well as a build up.
7.Arcs
An arc is a swinging or curved motion that most, if not all animation movements use, its generally used on characters as it gives more life to the characters animation, other wise it can look robotic if the arcs are not in place. Arcs are used in nearly all motions and cycles.
8.Secondary Action
A secondary action is an extra action that reinforces the first action or is an action that happens alongside the main action.
9.Timing
The more drawings used to make an animation means a slower action while the less drawing will result in a faster looking animation. The second part of timing is wether or not the animation is done in twos or ones. Twos is when there are two drawings on a frame and ones is when theres a single drawing on the frame. Timing also gets across the characters actions, so if a character moves there head quickly its a twitch or a dodge, but if its slower with more frames its a nod or come over here.
10.Exaggeration
This doesn't necessarily mean to enlarge and exaggerate the features of the character but to make things such as simple actions more interesting. By making a character do more emphasises the actions and secondary actions, so instead of just being shocked and saying something you make the character do an exaggerated leap back and wide eyes to show shock.
11.Solid Drawing
Solid drawing comes down to drawing skills and putting life into your animations, so symmetrical characters look very wooden as there isn't much variation, so more asymmetrical characters have more life.
12.Appeal or Character Personality
Making sure a character has charm and is appealing, this doesn't mean making them visually beautiful but more enjoyable to watch and listen to.