The Sandvik, Diener, and Seidlitz (1993) paper is another that has received widespread attention because it documented the fact that self-report well-being scales correlate with a number of other methods of measuring the same concepts, such as with reports by knowledgeable "informants" (family and friends), expe- ence sampling measurement, and the memory for good versus bad life events. A single factor was found to underlie measures using different...