The students have been using their own TI-Nspire handhelds since September 2008 and I started to use TI-Nspire Navigator with them in May 2009.  I used the File transfer and Screen capture features during the lesson. The TI-Nspire file also included some question that I was able to analyse using Class Analysis after the lesson.
The activity was excellent for the students to find out that angles subtending the same arc are equal or that the angle subtending the arc at the centre is twice the angle subtending the arc. The use of the Screen Capture view and being able to collect the students TI-NspireTM files enabled me to get a very good idea of the students’ learning during the lesson. There were a few students who would have benefited from more time on the exploratory tasks – they were less confident to answer the questions - whereas others were able to progress very quickly. Most of the students were able to generate the required theorems which meant we could move onto to justifying and proving them in the subsequent lessons.