Historically cycles were one of the early forms of animation through a device called the zoetrope where a spinning cylinder gave the impression that still drawings were in fact moving, of course the drawings then had to tell a repetitive story due to the nature of the zoetrope.
Cycles in animation today have their uses for such things as walk and run cycles, and many other actions to do with movement. However it is popular to also create cycles that are morphs, possibly due to the limitations a cycles narrative presents, a morph can overcome these issues.
How a scene is staged is very important to the overall story and how the audience perceives characters and the plot. A scene may have a lot going on in and around it but it is important for the animator to choose what to focus on as that is what the audience is going to see and perceive. It can cause elements of surprise to the storyline as the camera can focus on one thing, yet cut to another unexpected. It is important to consider what is included in the scene and how this can affect the audience emotion, for example shadows usually cast suspense and lightning can portray fear or horror.
Staging is usually not true to reality as the animator has to stage the characters at angles they would not be in; for example to converse they would probably be set at 3/4 angles to each other but this is so the audience can read emotion and expression.
Straight Ahead and Pose to Pose:
Straight ahead animation is usually spontaneous and fresh as the lack of control can help keep the whole process of drawing one frame straight after the other very creative as new ideas can be added as the animator goes along. However it is hard to judge the timing of the piece because of the lack of control, and in scenes where the layout or the background is busy, the technique will not work as it is hard to match the detail.
Pose to pose animation is carefully planned out, drawing key frames first and relating them to each other in size and action, the inbetweens are then filled in afterward. Scenes are always easy to follow because of the careful consideration, timings can be planned perfectly in the sense that the pattern of movement consists of short sharp movements as well as smooth flowing ones. However this of course takes time and resources, the downfall compared to straight ahead animation being that if a better idea is considered, it cannot be added as the scene has already been planned out.
Combining the two processes together is a winning combination, the pose to pose technique stops the straight ahead action from getting out of hand whilst keeping spontaneous. The use of all the other principles is very important to pose to pose action, such as timing and secondary action as it was these that developed the technique. Historically before the principles were developed, animators used to draw only in the straight ahead method and were only concerned with entertaining actions and the visuals.