real-time feedback [Anderson 1996], intelligent and responsive interaction [Anderson 1996], real
time interaction [Dholakia, Zhao, Dholakia and Fortin 2000], responsiveness to the user [Heeter
1989], immediacy of feedback [Ku 1992], responsiveness [Dholakia, Zhao, Dholakia and Fortin
2000; Ku 1992; Wu 2000]