When writing from a character’s point of view, authors should avoid the perception fallacy. This clunky kind of storytelling assumes that if a tale is being told from a specific character’s point of view, then all description must be filtered directly through that character’s senses and perceptions.

For example, an author would write:

Thales slammed the wax tablet so hard against the table that he heard the children laughing outside suddenly quiet. He threw his door open and saw a triangle of sunlight spread past him into the darkness. “You urchins, get out of here!” he shouted.

But readers don’t need to know that Thales “heard” the children laughing outside quieting or that he “saw” the triangle of sunlight spreading past him. Readers presume he can hear/see that. In any case, that he can hear/see it is largely irrelevant. Still, you’ll want to keep the detail of what was heard or seen in the story, as it moves the plot forward. Given this, a much better way to write the scene would be:

Thales slammed the wax tablet so hard against the table that the children laughing outside quieted. He threw his door open, and a triangle of sunlight spread past him into the darkness. “You urchins, get out of here!” he shouted.

As a story is being told through the lens of the author, filtering it through the character’s perceptions adds an additional lens that slightly blurs the story if only at the edges; such a lens is intrusive. Sometimes to get around this intrusiveness, the novice author will wrongly have another character tell our character what the author wants the reader to see; this actually adds a third lens to the story and often can be even more intrusive.

When the author persists in the perception fallacy, readers ultimately will become confused by exactly what is the author’s perception, the narrator’s perception, and any other character’s perceptions.

David Smith coined the term in an article for SFWA.