The May 1842 edition of Graham’s Magazine contains a review of volume 2 of Nathaniel Hawthorne's collection of short stories entitled Twice-Told Tales. The review was written by Edgar Allan Poe, in which Poe first proposes his theory of writing short stories that has since become known as Poe's "single effect" theory.

A skillful literary artist has constructed a tale. If wise he has not fashioned his thoughts to accommodate his incidents; but having conceived, with deliberate care, a certain unique or single effect to be wrought out, he then invents such incidents—he then combines such events as may best aid him in establishing this preconceived effect.

Poe elaborates on his "single effect" theory in a subsequent essay entitled "The Philosophy of Composition," which was published in Graham's Magazine in April 1846, in which Poe analyzes his poem "The Raven" with regard to his "single effect" theory.

Poe's "single effect" theory presents certain rules or guidelines that Poe believes are necessary to follow in order to write an effective short story. For example, Poe proposes that the story must be written to be read in one sitting of one-half hour to two hours, and no longer, which he believes reinforces the "totality" of the "single effect" of the story. Poe believes that every sentence in the story must build toward and contribute directly to the "single effect" of the story and that the first sentence is of utmost importance to the rest of the story.

If his very initial sentence tend not to the outbringing of this effect, then he has failed in his first step.

Poe emphasizes originality, brevity, and the totality of the story as essential elements of an effective short story. Poe equates writing a short story with painting a portrait, in which every word, like every brushstroke, contributes to the final, single effect of the story and the portrait as a whole.

This is the first sentence of Poe's short story "The Tell-Tale-Heart":

True!—nervous—very, very dreadfully nervous I had been and am; but why will you say that I am mad?

This sentence tells the reader that the narrator is "dreadfully nervous" for reasons as yet unknown, and someone, or perhaps more than one person, has told him that he is "mad," also for reasons as yet unknown.

The question of the madness of the narrator becomes, and remains, the focus of the story. The purpose of the story, the "single effect" of the story, is the exploration of the depth of the narrator's madness.

The madness of the narrator remains the underlying issue throughout the story, and true to his own theory, Poe introduces other issues during the course of the story that support and reinforce that single effect.

The first of these is the issue of the murder of the old man. Poe creates considerable suspense in the reader's mind while the narrator formulates, explains, and finally executes his plan to murder the old man. The second issue involves the suspense engendered by the seemingly interminable wait for the murder to be discovered, or, in the telling of the story of "The Tell-Tale Heart," revealed by the murderer himself.

In revealing the murder, the narrator reveals the true depth of his madness, and Poe achieves the single effect that he introduces in the first sentence of the story.

In "The Tell-Tale Heart," what single effect does Edgar Allan Poe create?

In his "Philosophy of Composition," Poe asserted that a well-written story would create a strong single effect. In "The Tell-Tale Heart," Poe methodically builds a feeling of dread that permeates the events in the story until the moment the killer's horrific crime is discovered by the police who come to investigate.

The opening of the story quickly establishes the madness of the narrator. His extreme agitation makes the reader fear that he has done something horrible that has had a destabilizing effect on him. From his first avowal, "I did not hate the old man," readers begin to understand that the old man had become the narrator's victim.

The feelings of dread are sustained as the narrator extends his confession of how he looked in on the old man night after night until he murdered him. The disposal of the body and the extended conversation with the police also work to worsen the feelings of dread until the story's abrupt conclusion.

In the short story 'The Tell Tale Heart' by Edgar Allen Poe, the author has one objective in mind - to quickly grab the attention of the reader, scare and intrigue the reader's curiosity,and hold it there til the end. You might want to explore the idea of the effect of suspense. This is where the author suggests an idea or possibility (usually a scary or creepy one!) to a reader by building upon the intrigue little bit by little bit, layer on layer.

Look at how he does this from the very first sentence and make some essay notes line by line. Look out for deliberate little clues he gives the reader as to what might happen next, how he builds character so the reader sees personalities (weird ones in this case) develop. Look at the images, sounds and effects he uses to create atmosphere.

You should find lots - Poe was renowned for throwing every technique in his writing repertoire at it!