Watson thought that a response is more likely to be connected to an environmental event (stimulus), if that stimulus-response is repeated regularly and with a short period of time between them (Child 1997, p.115). Thorndike showed that the student is less likely to repeat negative stimulus-responses, which therefore means that there will be an increase in the positive stimulus-responses, until a correct response is repeated regularly. The stimulus-response is then reinforced whenever a positive result is produced.(Child 1997, pp.114-121). Skinner made several conclusions from his findings in Operant Conditioning (Child 1997, pp.119-121). The steps taken in the conditioning process must be small. Regular rewards are required at the early stages, but once the conditioning is reflexive, rewards can be given less regularly. The rewards must come immediately or shortly after a positive response to ensure maximum effectiveness (feedback) (Child 1997, pp.114-121).When discussing learning theories, it's necessary to mention Pavlov due to the importance held in his work, even if it doesn't really directly affect the classroom. Pavlov pioneered the idea of classical conditioning with his famous experiment where he taught dogs to salivate, when a stimulus was applied, just before food was given to them. The dogs eventually associated the ringing of the bell with the arrival of food and salivated in anticipation of the food arriving (Child 1997, pp.116-118). Pavlov's work does not directly link to teaching in the classroom, but it does apply, in that the students may be conditioned, to have a memory or a response to an event that happens within the classroom environment.