1. A method for determining whether a media presentation device is in an on state or an off state, the method comprising: determining first and second characteristics of a signature associated with a signal representative of media content presented via the media presentation device; evaluating the first and second characteristics to determine first and second fuzzy contribution values, the first fuzzy contribution value representing a degree with which the first characteristic corresponds to the media presentation device being in at least one of the on state or the off state, the second fuzzy contribution value representing a degree with which the second characteristic corresponds to the media presentation device being in at least one of the on state or the off state; determining an audio test score based on a number of the first and second contribution values that indicate the media presentation device is in one of the on state or the off state; converting the audio test score into a third fuzzy contribution value; combining the first, second and third fuzzy contribution values to calculate an intermediate fuzzy score; and determining whether the media presentation device is in the on state or the off state based on the intermediate fuzzy score.