By Qsxy concepts or tests of the kinds introduced in chapter 7, synonymity sentences can be transformed into hypotheses that are, in principle, testable by relatively simple procedures. In practice, the questionnaire procedures schematically outlined in chapter 7 are not always applicable, and even in cases in which they might seem well adapted to the questions posed, they need careful discussion. In contemporary social science, the methodology of questionnaire methods has contributed much to the refinement of the rather crude techniques in use two or three decades ago, and it has also shown, by empirical investigations, how imperfections in the wording of the questionnaires and in other stages of the procedure influence results. In this chapter it is impossible to report on more than a handful of the empirical studies that have made use of Qsxy questionnaires or related kinds. Each study that has been undertaken with the aim of contributing to discussions on usage would require extensive space to be reported reliably. Some of the studies whose authors have used questionnaires identical or similar to the Qsxy questionnaires are listed in the references starting on page 505.