This paper reports preliminary validation studies on the WAIT technique. Within this research work, validation has been defined as the process of examining to what extent the technique is “well-grounded” or “wellfounded and fully applicable to the particular matter or circumstances”, with the term valid being derived from the Latin valere = to be strong (Oxford University Press, 2003, OED-online). In contrast with the term testing (discussed in Part II), validation encompasses the idea of a more formal scrutiny designed to give evidence that something not only works, but also works sufficiently well, i.e., is well founded. The validation of WAIT was carried out through specific studies, designed to measure particular attributes. It provides a more formal approach for accepting or rejecting the hypotheses under consideration, i.e., whether or not particular requirements were satisfactorily complied with, and the degree of compliance.