This observation instrument can best be characterized as event sampling. The observer is asked to observe for one relatively long and uninterrupted block of time (25 minutes) and to record on the "log" form only those "events" that pertain to the pedagogy of the math lesson (specifically, the skills/concepts covered and topic-centered question-answer interactions). Other events will be ignored unless they have a strong impact on the flow of the lesson. The "topic" form also involves summarizing only those events that are of interest.