Explanation : Freud believes, there are times when an event or an action is so painful that we cannot deal with the memory of it, so we repress the memory completely. By pushing the memory into subconscious and actively repressing it, we are unable to recall the memory or called forgetting.
Explanation : This is a change. Watson opposed behaviourism to the degree that it neglected the organism in behaviour. Therefore, he introduced 0 for the organism into the S-R formula to produce S-O-R.
Explanation : Ratio scale is an interval scale in which distances are stated with respect to a rational zero, rather than respect to the 'mean'. A rational zero is a location on an interval scale deliberately chosen for reasons other than the current data.