If a scene is told from a particular character's point of view (that is, no omniscient narrator), everything shown in that scene must be perceivable by the POV character. The perception fallacy is the common mistake of assuming that, if this is so, all description must be filtered through the senses of that character, rather than being presented directly. ("I got into the cab. I saw that the steering wheel had blood on it. I looked under the seat and found the knife." rather than "I got into the cab. The steering wheel had blood on it. The knife was under the seat.") The difference is whether the POV character is intrusive and disruptive or unobtrusive. This often has several unintended negative consequences: # Reality is filtered through an extra lens. Instead of saying "rain poured down" the author writes "I felt the rain pour down". A storey always has one philtre — author telling reader — and good authors generally try to make the author as unobtrusive as possible. Adding this second philtre — author telling character to tell reader — is not only uneconomical, it is also often intrusive. # Feeling trapped into the restriction that all information must come to the point-of-view character, with the result that characters often rush onstage to tell the point-of-view character something. This is even worse than the first problem, because now we have a third filter: character telling character telling author telling reader. # Confusion between the perception of the author, the narrator (if any), and the POV character.