I have already covered the fact that both straight ahead and pose to pose methods offer certain advantages for different types of animation. However a combination of the two when animating will give the spontaneity of the straight ahead method whilst the pose to pose element will stop it from getting out of hand.
In these cases the animation can be planned out in the pose to pose animation format whilst using none of these in the final format preferring the straight ahead methods. However straight ahead animation will rarely work if there are busy backgrounds or a strong perspective in the layout because the layout will provide limitations. Historically, this haphazard method was used by the first animators as they were more concerned with entertaining actions. The pose to pose method developed eventually after the finding and stressing of the importance of using the principles of animation by Disney studios.