  Computer-assisted modelling is an essential approach to design new devices.
It speeds up the process from the initial idea to an actual device and saves
resources by reducing the number of built prototypes. This is also a
significant practical motivator behind scientific research in contemporary
high-temperature superconductor (HTS) AC loss modelling. However, in the
scientific literature in this field, consistent practices about modelling
terminology have not been established. Then, it is up to the reader to decide,
what is the true intent and meaning of the authors. Consequently, the
interpretation of such literature might be very much reader-dependent.
Moreover, an inseparable part of the whole modelling process is the development
of modelling approaches and numerical methods and comparing the predictions
obtained via modelling to experimentally achieved results: It is commonplace to
discuss the accuracy of modelling results or the validation of a model. In this
paper, we discuss the terminology related to theories, models and experiments
in the context of HTS AC loss modelling. We discuss the recursive nature of
theories and models in this context, discuss the compatibility of discrete
formulations of physics utilized in our field with the corresponding continuum
descriptions, as well as with intuition, and interpret the perceived meaning of
validation of a self-consistent model, shedding light on the relationships
between theories, models and measurements. We present our view on understanding
these relations in the familiar context of AC losses in HTS. As a result, we
end this paper with four conjectures describing our views.
