QOL measurement is an enormous field that spans multiple disciplines (Felce & Perry, 1995; Phillips, 2006). Calls for its unification, clarification, or abandonment have been common for nearly four decades (Abeles, Gift, & Ory, 1994; Rapley, 2003). Improving QOL conceptualization and measurement is an important endeavor because of the many ways in which QOL measures are used, and the significant effects of these QOL applications, including influencing decisions about drug efficacy and cost effectiveness, and subsequent health policy decisions. Amidst the hundreds of definitions and scales and thousands of published papers, QOL scientists agree that an individual's personal evaluative process is of utmost importance in the formulation of QOL. Yet, there have been few attempts to measure this process, and no attempts to manipulate it. This dissertation sought to examine, quantify, and manipulate a portion of the personal evaluative process in self-reporting an individual's QOL by examining it through the lens of social and temporal comparisons within the bounds of the WHOQOL-BREF. Using a mixed-methods approach, the results of this dissertation demonstrated that social and temporal comparisons play a significant role in the personal evaluative process of self-reporting QOL, and that manipulating what type of comparison an individual uses can significantly impact the numerical outcome of the WHOQOL-BREF. Results are discussed in terms of impact on the use of QOL as an outcome measure in research, policy, and practice.