The Mythical Distinction Between Measurement and Prediction – Unifying These Approaches Through Estimation Theory

Over decades, the literature on educational and psychological assessment of latent attributes has proposed a number of approaches for obtaining and interpreting scores from tests and questionnaires, with measurement and prediction standing out. These approaches have traditionally been portrayed as fundamentally different, and it has been claimed that they would pursue different goals and have distinct interpretations. However, such views might reflect a myth – one perpetuated through repetition rather than theoretical necessity. With this article, we aim to challenge this long-standing belief by arguing that the distinction between measurement and prediction is not necessary. Specifically, we propose that both the measured score and the predicted score can be viewed as estimators of the same underlying quantity, the true score, thereby unifying them under the broader framework of estimation theory. This unification helps clarify conceptual relationships between assessment approaches and promotes greater coherence in how scores are interpreted across research and practice.