A conspiracy theory is an explanation for an event or situation that invokes a conspiracy by sinister and powerful groups, often political in motivation, when other explanations are more probable. The term has a negative connotation, implying that the appeal to a conspiracy is based on prejudice or insufficient evidence. A conspiracy theory is not simply a conspiracy; instead, it refers to a hypothesized conspiracy with specific characteristics, such as an opposition to the mainstream consensus among those people who are qualified to evaluate its accuracy.