  Equating users' true needs and desires with behavioural measures of
'engagement' is problematic. However, good metrics of 'true preferences' are
difficult to define, as cognitive biases make people's preferences change with
context and exhibit inconsistencies over time. Yet, HCI research often glosses
over the philosophical and theoretical depth of what it means to infer what
users really want. In this paper, we present an alternative yet very real
discussion of this issue, via a fictive dialogue between senior executives in a
tech company aimed at helping people live the life they `really' want to live.
How will the designers settle on a metric for their product to optimise?
