You could give relatively simple verbal intensional definitions to try and lead someone to the bird cluster, yes. But if you had someone who wasn’t practically accessible through those verbal communications, how would you do it?
You’d have to show extensional examples, positives and negatives, and indicate the value of each example by some clear and consistent signal.
You couldn’t give all possible extensional examples, so you would have to select some. And you couldn’t give them all at once, so you’d have to present them in a particular order.
What is the theory for finding optimized selections and orderings of examples for leading the learner to the cluster? How does that theory extend to the more complicated case where you have to communicate the subtypes within the “bird” cluster?
This is one of the many things that the Theory of Direct Instruction that’s presented in Engelmann and Carnine’s text Theory of Instruction: Principles and Applications addresses. [They call it a “multi-dimensional non-comparative concept” (non-comparative” meaning the value of any example is absolute rather than relative to the last), or “noun” for short.]
And of course, if you had to select and order the presentation of simple verbal definitions/descriptions as examples themselves, the theory would also have application.
Please see here for a clarification of what “someone who wasn’t practically accessible through those verbal communications” means, and a more concrete example of teaching the higher-order class ‘vehicles’ and sub-classes.