A definition of terms in this research area is presented. A general approach for applying nondestructive quality evaluation (NDQE) to horticultural crops, for both fresh and processing purposes is discussed. The approach includes consideration of the importance of biochemical, morphological and physical parameters of quality. The objective and subjective determination of single and multiple parameter judgements of quality at different stages of physiological development is a critical part of this approach. The concept of "Optimum Quality Range" is presented in relation to the development of nondestructive quality evaluation techniques and applications.