Behaviour therapy is used for a number of methods of psychotherapy. Ivan Pavlov found that it is possible to "learn" how to react to a stimulus. His method is known as classical conditioning today. Behaviour therapy tries to use this knowledge to change the behaviour of people. In that way, people "learn" how to cope with their fears, for example. In a similar manner, people can be helped to cope with a number of mental disorders. One well known kind of behaviour therapy is exposure therapy: People with fears are "exposed" to them, and learn how to cope. As an example, someone who is afraid of spiders will be exposed to spiders.