Which of the following is NOT a characteristic of a short story?

One of the defining characteristics of a short story is its brevity, which allows it to be consumed in one reading session, making it possible for the reader to grasp its themes and messages quickly. The essence of a short story lies not in its length but in its ability to create a strong impression or convey a specific effect within a minimal framework.

Short stories typically focus on a limited scope, often developing a single theme or exploring a singular point or effect, which enhances their impact. They include essential elements like plot and character development, which are integral to conveying the story’s core message. By contrast, being lengthy contradicts the very nature of what constitutes a short story. Therefore, indicating that a short story "must be lengthy" distinguishes it from the true characteristics that define the form.