This presentation motivates and introduce the aims and scope of the symposium on "Testing Knowledge", which resulted out of a working group and will conclude in a collective publication.
We explain why it is fruitful to describe the twentieth century as a century of standardized testing—and of the recurring question of a test’s “validity”. This historiographical lens allows us to address how scientific reductionism and bureaucratic priorities—as well as ideas of fairness, feasibility, and marketability—have shaped the development and institutionalization of standardized tests. Be it a diagnostic test in psychiatry, a randomized controlled trial in evidence-based medicine, or so-called animal models in pharmaceutical and chemical regulation—these and further examples in the history of the health and human sciences make tangible how routine testing has become a pervasive aspect of modern life, informing decision-making in many spaces, including clinics, courtrooms, and public administration. We argue that it is particularly important to assess processes of validation as technically complicated, institutionally entrenched, and negotiated by a constellation of actors including scientific experts, national administrations, international organizations, and activists. Thereby, we also offer a critical perspective on the hegemony of Western actors and imperial thought in setting the methods that certify knowledge for international policy making and global markets. In examining the twentieth century as a veritable testbed for practices of validation and decision-making, from individual life and health to the testing of entire populations, infrastructures, and environments, we strive to historicize and localize what became global standards of validating knowledge on human health.

In the 1880s U.S., conflicts among government and manufacturing chemists over the contents of artificial fertilizer generated a scientific and social need to standardize testing practices. In 1884, government chemists formed the Association of Official Agricultural Chemists (AOAC) to develop, test, and approve standard methods for determining agricultural products’ contents, thereby establishing nationwide regulation of a commercial enterprise. On the basis of multi-laboratory “collaborative studies,” the AOAC adopted analytical methods that were judged to produce sufficiently uniform results—a process later known as “validation.” AOAC methods became the foundation of U.S. food law. Nearly a century later, in the 1970s, officials confronted similar challenges with toxicity testing methods, which were insufficiently reliable. The AOAC rose to the challenge, attempting to translate its epistemological monopoly over validated methods in analytical chemistry to toxicology. But this time the AOAC failed: most toxicologists resisted standardization and methodological uniformity failed to produce uniform results. Where the AOAC failed, the Organisation for Economic Co-operation and Development succeeded, bringing together scientists and regulators from across the industrialized world to establish standard methods for evaluating chemical risk. There, epistemic qualms about standardization were overridden by social and political pressures to standardize practices to facilitate regulation and trade.

This paper narrates the origins of validity theory in the postwar US psychological profession. Although the language of test validation is fundamental to how social science is written, in practice applications of quantitative social measures are scarcely regulated as theories of validity describe. This paper traces the origins of this professional arrangement to the work of the 1950-1954 APA Committee on Test Standards on the Technical Recommendations for Psychological Tests and Diagnostic Techniques, which produced an early and influential theorization of validity. Behind-the-scenes editorial negotiations between two psychologists (psychometrician and committee chair Lee Cronbach; social psychologist and former APA president Gordon Allport) reflect a tension between two competing uses of psychological tests: as career objects accreting attention and reputation, or as technical objects underwriting comparative statistical analysis. Allport and Cronbach’s dispute and the subsequent compromises that produced a theory of validity effectively bound methodologists’ authority to a theory-driven notion of scientific conduct, rather than expanding their jurisdiction into its ethical or democratic
dimensions.