ABSTRACT
This chapter reviews conceptual approaches to the perceived quality of life (QoL). Because it is near impossible to separate out where health and non-health aspects begin and end, and the duality of the nomothetic and idiographic is forbidding, the chapter reviews both approaches and blurs the distinction between health and non-health. All measurements include assumptions about the nature and value of the constructs used in the measurement process; yet the role of theory in developing and interpreting QoL measures is often neglected. The measurement operations used to assign numbers to concepts and domains of QoL also reflect theoretical assumptions. Theoretical relationships among disease, its indicators, and functional status are sometimes possible to specify; however, relationships among measures of function and feelings of positive well-being are often difficult to predict with any precision. The concept of "need" has been used by many analysts, most notably Abraham Maslow, to denote a drive or some inner state.
