Students on their cell phones in the hallway, what was going on in this classroom?

Google_voice
I observed a class the other day and I observed students talking on their cell phones in the hallway, other groups of students sitting at their desks and talking, and later on a popular music video was projected onto the large screen in the front of the room. Some administrators might have been bothered by what I saw, but I thought it was one of the best lessons I had seen all year. Why? The students were fully engaged in the learning. Let me explain.
 
The class I observed was a high school Spanish class. The day before the lesson I observed the students began writing a dialogue between two or three people in Spanish using the vocabulary words they were learning as part of the unit. They continued this activity and began practicing speaking the dialogue. When the students felt ready to record their conversation they went into the hallway and using their cell phone they called the teacher's Google Voice number. Each group's dialogue was stored in the teacher's Google Voice inbox. Since she has each student's contact info in her Google Voice account it associates a phone number and the student's email to each student recording. At the beginning of the lesson the teacher went over the rubric she would be using to grade the recordings. She emphasized that she would be listening to their voice and that they should try to sound like a native speaker. When the students completed the recording she played a Spanish music video. She handed out the lyrics in Spanish with some of the words missing. The students had to listen and fill in the blanks. The next time through the video she supplied a word bank to assist students who were having trouble.

After the lesson the teacher said to me she was sorry that I did not get to see her doing that much. I told her it was one of the best lessons I had seen all year. I think she was somewhat surprised by my statement, but I reiterated to her that for almost the entire period the students were either reading, writing, listening to, or speaking Spanish. The NJ Core Curriculum Standard for World Languages emphasizes the ability for students to communicate in the target language. I must add that this particular teacher is excellent at what she does. She works very hard and has developed an excellent rapport with the students in her classroom. There was absolutely no misuse of the student cell phones. The students were very well behaved.

As a side note our Spring Break was to start in a day and the teacher was going away with her family. She has a smartphone running the Android operating system. Google Voice is a native app on her phone. If she wanted, while she was sitting on the beach, she could listen to the student recordings and send an email or text message to each student letting them know how they sounded. She could have even sent a copy of the recordings to each of the students for them to listen to (For non-Android phones you can access Google Voice via the web). Without Google Voice and student cell phones how would you duplicate this lesson? What would it cost the district? How much time would it take? Would you be able to archive the recordings and share them with the students?

Additional side notes - For this lesson the cell phones worked exactly as they should. The students had no problem using their own phone and at no time did they use the school network. Easy to use and no glitches. How often can you say this about classroom technology.

How do you record student conversations at your school?