Verification activities are a type of laboratory exercise in which students confirm information that they have previously learned. For example, students may determine the effects of temperature on the volume of gas in balloons as a verification or validation of Boyle's Law. In a verification activity, the conclusion is not a surprise, the students are merely determining if the answers they get correspond to known information. A verification activity may, however, be a discovery activity for students who do not already know the outcome, perhaps because they did not understand the concept or law or were absent during a class discussion, exposition, or demonstration of the concept. (See Laboratory Activity)