A prevalent theory about the cognitive aspect of humor is that most humorous stimuli are characterized by incongruity that is first perceived and then resolved. However, the combination of incongruity and resolution is not sufficient for constituting a joke--resolution should be inadequate as well. In other words, resolution is brought about by the receiver's disregard of an essential piece of information that is not explicitly stated but is typically assumed or inferred and that actually makes the initial information unambiguous. Thus, the incongruity only appears to be resolved because the resolution conflicts with valid reasoning made previously. The resolution is seemingly appropriate but virtually inappropriate. A joke is understood when the listener realizes not only the incongruity or its possible resolution, but also the predication of the resolution on overlooked knowledge that seems essential for proper interpretation. In contrast with the concept of a joke, which is a category of stimuli, funniness is a continuum, not a category. Many factors, none of which is either a necessary or a sufficient condition in itself, may contribute to the amount of funniness, independently or interactively. (HOD)