Fiction writers tend to fall into two broad camps: those who overwrite and those who underwrite. And, while a novelist may be able to get away with writing a spare story, a thin story will never ignite the reader's imagination. A spare story is one in which the writer deliberately chooses to pare down every element, using a small cast of characters, only one or two subplots, and little exposition and description. A well-crafted, yet spare story can work when every word counts and there is enough information to take the reader on a fictional journey. Ernest Hemingway usually wrote spare stories, but readers still feel immersed in his stories and understand the ramifications of the plot on the lives of his characters.
A thin story, on the other hand, is not based on deliberate choices, but rather on inexperience. In a thin story, the writer does not supply enough sensory data, creating a story line that can't be followed with confidence because of a lack of needed information. Spare stories spark the reader's imagination, but thin stories do not have enough data to do so, leaving the reader confused. In these anemic offerings, the reader is often adrift, longing for detail to place him in the scene, a hint about the themes or deeper meanings, or any doorway into the writer's intentions.
Jessica Page Morrell, Between the Lines, 2006