  Engagement is a fuzzy concept. In the present work we operationalize
engagement mechanistically by linking it directly to human behaviour and show
that the construct of engagement can be used for shaping and interpreting
data-driven methods. First we outline a formal framework for engagement
modelling. Second we expanded on our previous work on theory-inspired
data-driven approaches to better model the engagement process by proposing a
new modelling technique, the Melchoir Model. Third, we illustrate how, through
model comparison and inspection, we can link machine-learned models and
underlying theoretical frameworks. Finally we discuss our results in light of a
theory-driven hypothesis and highlight potential application of our work in
industry.
