Editing is the final step to finishing a story. It helps the producer to mold the story and shed it in the light they want. This process can be time consuming and is aesthetic intensive.
The ability to provide lots of information in a simple fashion helps to increase the focus of the story for the audience. The better the audience understands the focus the more clearly your idea or opinion is expressed as a producer. This can be accomplished through techniques such as shot order, timing, and shot relationship.
Shot order is deals with the progression of scenes. It is imperative for creating focus and simplifying the chain of events for the audience. If you have a shot order that is not progressive, and each scene does not build on the next it can lead to confusion amongst the audience. Looking at the comic below you can see that if the frames were out of order it would be very confusing for viewers to understand the producers intentions.
Shot relationship has similar guidelines as shot order. If the relationship between the shots is not easily distinguishable for audiences it can also cause misunderstanding for audiences. At the same shot relationship can be used to show contrast between characters of events in the different scenes and can leave the audience to the own devices to decipher what the producer was getting at.
Timing is the most difficult part of the editing process. It can drastically change the length of scenes, dragging out some events while cutting others short. In the film business editors have to focus on timing as most viewers can become bored if a movie is too long or irritated if it is too short. This article by Professor James Cutting of Cornell University examines a formula that is used by Hollywood producers to ensure that the length of scenes is just right.
CMD Communications Blog 