This commentary raises conceptual issues related to recent efforts to develop measures of subjective well-being (SWB). Specifically, Hills’ and Argyle's (2002) article on the development of the 29-item Oxford Happiness Questionnaire (OHQ), and its predecessor, the 20-item Oxford Happiness Inventory (Argyle, Martin & Crossland, 1989). Instead of assessing the structure of subjective well-being (SWB), items of the OHQ tap into self-esteem, sense of purpose, social interest and kindness, sense of humor, and aesthetic appreciation. The item content of the OHQ fails to differentiate the assessment of SWB from the predictors, correlates, and consequences of SWB. In contrast to published SWB findings with other measures, data are presented suggesting that the OHQ has artificially inflated correlations with those constructs tapped by the OHQ: self-esteem, sense of purpose, and social interest/extraversion. The operationalization of SWB by the OHQ is not based on relevant definition and theory and appears to invite nonrandom error into the study of SWB. The article concludes with an appeal for the use of more stringent conceptual and analytic approaches.