Practitioners in health sciences education and assessment regularly use a range of psychometric techniques to analyse data, evaluate models, and make crucial progression decisions regarding student learning. However, a recent editorial entitled "Is Psychometrics Science?" highlighted some core epistemological and practical problems in psychometrics, and brought its legitimacy into question. This paper attempts to address these issues by applying some key ideas from history and philosophy of science (HPS) discourse. I present some of the conceptual developments in HPS that have bearing on the psychometrics debate. Next, by shifting the focus onto what constitutes the practice of science, I discuss psychometrics in action. Some incorrectly conceptualize science as an assemblage of truths, rather than an assemblage of tools and goals. Psychometrics, however, seems to be an assemblage of methods and techniques. Psychometrics in action represents a range of practices using specific tools in specific contexts. This does not render the practice of psychometrics meaningless or futile. Engaging in debates about whether or not we should regard psychometrics as 'scientific' is, however, a fruitless enterprise. The key question and focus should be whether, on what grounds, and in what contexts, the existing methods and techniques used by psychometricians can be justified or criticized.