Dave Morrison does a wonderful and quick explanation of the improvisational way. Makes me realise that the twenty minutes I got at the Do Lectures was a luxury.
Also, I particularly liked how he demonstrated ‘Yes And’ though, as normal, I do take issue a little with the implication that you should always say ‘yes’ (I bang on about this at some length in ‘Safekeeping’, Chapter 6′ of ‘Everything’s an Offer’).