'''Define then discuss''' is a (controversial, but generally followed in practice) pedagogical principle where, when a new idea is introduced, the relevant term (called the ''definiendum'')
are first defined as precisely as possible or necessary, and ''then'' their significance is discussed. The "discussion" could be carried out interactively, using the formally presented definition as the starting point for exploration.
The ''discuss'' could include discussion of:
* Having a definition to fall back to gives learners a bare minimum they can always rely upon. For an approach that does not begin with a definition, learners may be more easily disoriented, and there's a greater chance that they may take away nothing from the learning session.
* Constructing examples or deducing behavior and attributes based on a purely formal definition draws on the learner's background knowledge and also helps practice the retrieval of that knowledge, this allowing for [[spaced repetition]] and [[overlearning]] of past knowledge.
* The approach is often more efficient time-wise than alternative approaches such as
the [[examples first]], even though the latter may engender a deeper understanding of some aspects of the definition. In some cases, time constraints favor this approach.
Note that any comparative analysis would also consider whether the alternate methods work well in the context. Some definitions may be fertile for exploration, but the [[examples first]] approach may also be very promising. In contrast, some definitions may be extremely opaque regardless of the approach we use.