Coaching Session - Who's Engaged?

I recently completed a couple of classroom observations with student teachers who had identified student engagement as one of their personal learning goals on the action plan for the observed lesson. We agreed I would collect data on student engagement at five-minute intervals using an annotated seating chart.

Here's the diagram from one of the classes. Letters "A" through "H" mark students who I judged were not on task at at least some point during the five minute time index of the survey.

What do you notice? What questions do you have?

Here's the diagram from another class at a different school. The seating arrangement shifted mid-lesson when students began to work in pairs; these pairings are indicated as bolded connections on the diagram. 

Again, letters "A" through "H" mark students who were not on task at that time index of the survey. You can see a chronicle of this lesson below the chart.

Time Index	What was happening at that moment?
"A"  0:05 minutes	Bell-ringer / Focus lesson.   One stu. reading a book (right side).
"B"  0:10 minutes	Handout / Launch.   No disengagement visible at this moment.
"C"  0:15 minutes	Students Pair Up.    No disengagement visible at this moment.
"D"  0:20 minutes	Pair-work; Teachers Circulate.    Teacher works with back row/center pair.
"E"  0:25 minutes	Pair-work; Teachers Circulate.    Teacher works with pair in front of back row/center.
"F"  0:30 minutes	Front/center pair: "We're finished."  Teacher preparing to call class back together.
No data  0:35 minutes	Student volunteers present at board;    Concurrently: Teacher dialogues with whole group.
"G"  0:40 minutes	Continues.
"H"  0:45 minutes	Continues.    Wrap.
END 0:50 minutes	End.   Students dismissed.

Again, what do you notice? What questions does this raise?

It was surprising to me how much I missed in terms of what the teacher was saying and doing while I was focusing my efforts on monitoring engagement like this throughout a lesson. So this raises another question for me:

What do I focus on when I am teaching? 

And by focusing on that, what am I not seeing?

I welcome your thoughts on these questions.

(Revised 3/6/14 to add a second engagement monitoring diagram.)