In higher education, classroom observations are usually conducted to evaluate or provide the teacher with feedback about instructional practices. Typically, a single observer sits in on a class and takes notes about the instructor’s performance. Observations tend to be done infrequently and play little, if any, role in instructional improvement.
In contrast, teachers observe research lessons to gather evidence about how the instructional activities affect student learning and thinking. In lesson study there is much less emphasis on observing the teacher and much more emphasis on how students respond to the lesson. Observation during a lesson opens a window on student thinking. For some instructors this is the first time they see a lesson through the students’ eyes, and focus on how students interpret and make sense of the material.
To prepare for the observation teams decide: who to observe, what to observe, how to record data, and how to coordinate the observation.
Who to observe. Teams may focus on specific individuals or groups of students (e.g., students who differ in ability and performance in the class). Or, if the lesson involves group work, the team may pre-select certain groups for observation.
What to observe. Teams identify in advance what types of data to observe and collect (e.g, student-student interactions, types of questions students ask in class, student responses to instructor questions, students’ written work, etc.). An important focal point of observation is student thinking directly related to the lesson’s learning goals. For example, in one of our psychology lesson studies, we defined understanding—a major goal of the lesson—as the ability to predict and explain certain types of social behavior. During the lesson students engaged in several exercises that involved prediction and explanations. Observers attended closely to how students formed and revised explanations in these episodes.
Instructors also attend to broader features of teaching and learning during the lesson—how students approach the class, how they interact with one another, how they respond to the instructor, and variations in student behavior. In one of our own research lessons, students worked in small groups on several tasks, and we used their group summaries as evidence of their learning. However observers noticed that several groups were off task during the lesson. Worse, they were able to fake a credible response when asked to give a group summary of their ideas. Had we not observed this activity, we might have inferred from their summaries that the small group task was a key to their learning.
How to record data. Data collection techniques vary from relatively unstructured note-taking to the use of checklists and rubrics. Teams adopt strategies best suited to their research lesson. Three common techniques:
1. Field notes are detailed written notes by observers, and a good way to record the entire lesson. When there are multiple observers, it is possible to get detailed observations of specific students or groups of students.
2. Focal questions orient observers to key features of the lesson and student responses (e.g., “To what extent do students challenge and support one another’s ideas when they work in small groups?”; “In what ways do students exhibit interest or disinterest in the lesson?”). Focal questions help insure that observers will attend to specific aspects of the lesson.
3. Checklists are useful ways to monitor specific types of responses (e.g., the number of times students make metacognitive comments such as “I don’t understand this.”; “Oh, that’s what he means? I was thinking just the opposite.”).
Coordinating the observation. The team prepares Observation Guidelines prior to the lesson. These include a copy of the lesson plan and a detailed description of what observers should do and attend to during the lesson (e.g., take field notes, answer focal questions, use checklist, etc). See an example of observation guidelines for a psychology lesson
Bill Cerbin
Lesson study is a window into the "full act of teaching" and thus provides richer information about teaching effectiveness than the disparate items typically included in teaching portfolios—namely, course syllabi, assignments, exams, grade distributions, student evaluations, teaching philosophies, etc. More significantly perhaps, lesson study shows how vision, design, enactment, outcomes, and analysis are integrated in actual classroom practice.
A major challenge in lesson study is to observe student learning as it takes place during the lesson. This involves observing how students engage and try to make sense of the subject matter. If we know more about how students learn, we should be better able to improve the lesson. 
Imagine what teaching would be like if you were able to refer to lesson studies on the topics you teach? Instead of starting from scratch—as most of us do—you could build on the work of others, adapt strategies and materials to your classes, and anticipate the kinds of problems and difficulties students might experience.