Operational definitions are definitely alive and well within psychology. For example, Underwood wrote, "Most experimentalists in all disciplines tacitly or actively accept operational definitions as a means of specifying the empirical basis of a discipline. That is, they use operational definitions in order to define the phenomena of nature with which a discipline concerns itself (1966, p. 299). Several other authors of texts on experimental design echo Underwood's sentiments (e.g., Bachrach, 1965; Christensen, 1980; Kidder & Charles, 1986; Lyons, 1965; McGuigan, 1983; Myers, 1980; Neale & Liebert, 1973; Solso & Johnson, 1984).