This chapter is devoted, first, to the description of the 477 datasets that were initially selected for analysis in this survey. It presents statistics on various characteristics of these datasets, on the types of analysis that were employed, and on the general outcomes. Second, it tells how the results of the survey are to be presented in subsequent chapters.

Since the initial preparation of this chapter and its tables, a handful of datasets were dropped from the database for various reasons, chiefly because some were found not to be in the public domain. Also, a small number of datasets – fewer than a dozen – were added to the database, either because they had earlier been overlooked or because they were published subsequent to the initial selection of datasets that occurred in 1985. Nevertheless, the tables of information presented in this chapter, based on the datasets initially selected, can be taken to give trustworthy (albeit approximate) characterizations of the datasets actually employed in the survey.