WHY DOES STORY STRUCTURE EVEN MATTER?
The question of whether and how much story structure matters appears to be one that can elicit rather a lot of debate in some quarters. My increasingly strong opinion is that structure matters a great deal for a number of reasons, three of which are audience expectations, professional craftsmanship, and ease of construction.
In modern society, readers encounter many different kinds of writing on a regular basis. We develop expectations for each kind of writing, depending on the context and purpose of the written material. For example, we expect an advertisement to be brief and informative (and heavily biased). We expect a news report to contain relevant factual information regarding an event that has happened. We expect an article in a scholarly journal to contain an analysis of research results.
We also expect stories--whether in television and movies, books and magazines, or old-fashioned water-cooler gossip--to conform to a basic structural format. When a work of fiction doesn't conform to the "story" structure, audiences feel disappointed and let-down. If your reader wanted an essay, or an article, or an advertisement, or a textbook, she wouldn't be reading a novel or short story to find it.
Imagine picking up a novel, only to discover that the writing in it is actually a lengthy advertisement that does nothing but extol the virtues of a particular brand of breakfast cereal. Nutritional information and serving suggestions, even when written out in sentences and paragraphs, with handy chapter divisions, do not constitute a story. Neither does a well-crafted political essay or a beautifully written description of a beach in Mexico.
If you promise your reader a story, you'd better deliver something the reader recognizes as a story, so that your reader will go away satisfied--and hopefully come back again for your next story.
A basic understanding of standard story structure is a valuable tool for crafting stories at a professional level. Some authors write intuitively first, and then analyze and adjust the story through multiple drafts until it takes on a solid, cohesive story structure. Other authors outline the structure first, and craft the story within the framework of that structure. Whichever approach is used, the creative piece must be brought into general conformation with the standard story structure.
Why? Because if it doesn't conform to the structure, it isn't a story. Just like a chair can only be a chair if it conforms to certain basic structural expectations. Just like there are certain structural elements that make a waffle a waffle instead of a pancake.
I can hear some of you protesting already. "What about creativity?" you ask. "What about originality?" Not to worry. There's plenty of room for creativity and originality within the standard story structure--just like there is with chairs. After all, a rattan papasan, a stainless steel bar stool, and a vinyl-covered dental chair all conform to the basic chair structure, even though they are very different from each other. But you're going to have a hard time convincing anyone that a waffle iron is a legitimate form of chair. Finding (or making) space for creative originality within the standard form is part of the fun of writing stories. And it's part of what separates professional-level writing from amateur efforts.
Another fun thing about knowing the "rules", or structural expectations, is that this knowledge enables you to break them intelligently. This is true in every form of the creative arts. There's a difference between clumsily breaking rules because one is stumbling blindly through the creative process, and intentionally subverting expectations in order to guide a reader's experience--and agents, editors, and experienced readers can definitely tell the difference. You need to know the difference too, if you want your work to stand out as professional.
(The same principle applies, by the way, to breaking rules of genre, character arc, and even grammar and spelling--a professional-level writer breaks the rules selectively, with an understanding of the effect that will be produced by stepping outside that particular expectation. Amateurish rule breaking just looks like mistakes.)
Ease of Construction
Everyone's writing process is different, but I find it much easier to construct a story when I am able to wrap my mind around the figurative "shape" of the thing I am attempting to create.
Knowing the basic structure of a story helps me keep my story on track during the first draft. I spend less time staring at a blank screen with no idea of how to proceed. There are fewer plot holes in my first draft that have to be fixed later. And I don't waste time writing large chunks of superfluous text that have nothing relevant to add to the story at hand and have to be edited out.
A solid understanding of story structure gives a fiction writer a great advantage in fulfilling audience expectations and efficiently producing professional quality work.