The answer for the above question would be that, we do not need
Interaction between humans and the programs, if were a problem in solution type. But we have started building programs for all the cases .in case of this type it need a interaction wit the people which in turn will provide the input from t them. Therefore, we could classify them into two types. They are
1. solitary
2. conversational
In the second type, each step needs an interaction with the user,