Teacher: Dr. D. Roemer
Class: SP11 (E band)
Topic: Kinematics- motion
Date of Observation: 9/22/94
Date of Conference: 9/23/94
September 26, 1994
Dear Dr. Roemer,
You began this lesson by distributing a hand-out marked "Lesson 7" and containing the aim, "What is the slope of a graph?" (see attached) You presented an overview of the lesson by saying, "in today's lesson we will be learning that all graphs are connected to each other" and went on to describe how the slope can be determined for three types of graphs - a straight line graph describing distance vs. time of a moving object with a constant acceleration, a straight line graph describing an object with no acceleration, and a curved graph which described the motion of an object with changing acceleration. You announced that the class would be getting a quiz the following week that would contain a single problem for them to solve. You then went to question number two on the hand-out and showed the class how to solve the problem by doing the problem at the board. Next you asked the students to face a partner and to discuss the acceleration of an object that you were throwing upward (from problem #1 on hand-out). After you called on a student to describe the object's acceleration you told the students to spend the remaining twenty minutes to the band working on the other problems on the sheet.
In our post-observation conference you indicated to me that you were unhappy with the way the lesson went for the following reasons:
1. You spent too much time telling the students information. The lesson was predominantly a lecture and you felt the students should have been more involved. I indicated that you gave the students little opportunity for feedback. Once you had made a point, instead of asking a question or having students find the slope of a graph, you simply went on to the next example. You had no way of knowing whether the students understood the first example you presented. This is one danger of the lecture style of teaching.
As you are well aware, students need to construct their own knowledge. They need to attach the new information to something they already understand. By simply lecturing, you are attempting to treat them as empty vessels into which you can pour knowledge. It doesn't work, they don't understand, they become frustrated and so do you. In this lesson you could have given them three different types of motion problems to solve and let them draw the graphs to illustrate the three types you wanted to cover. Students could
come to the front of the room, put the problem on the board and show the graph. The students should have been allowed to draw the conclusions about the graphs and the acceleration. (Don't draw graph grids on the board by hand. You can use an overhead transparency of a grid and simply erase it and use it over and over again.) When you do ask a question, don't rely on a single answer from a single student. Pass the question around. Get feedback from several students to make sure that others understand. Ask
others to comment on the first person's.
2. You had no motivation for the lesson and no demonstrations to go along with the lesson. I indicated that you might want to open the lesson with a discussion of the recent US Air crash. The newspapers (or the investigators) reported that it took 23 seconds for the plane to hit the ground once it began to fall. Have the class work backward and find out what altitude the plane was at before it fell. Have them draw a graph of the descent of the plane and determine the slope of the line and interpret whether acceleration was constant or changing. To develop ideas for motivations and demonstrations for each lesson speak with the others teaching Physics as well as Mrs. Kesner and I. We will all be glad to offer you assistance.
3. Although the aim of the lesson focused on graphs, the bulk of the lesson was focused on solving motion problems. I indicated that you should have used the graphs to support the motion problems. The problems themselves are talk and chalk. The graph converts this into a picture. They should have been used to support the problems and not to replace them, as in the suggestion in #2 above. As you seemed to understand, the stated aim, in this case, "What is the slope of a graph?" should be the focus for a lesson. Since this was not what you wanted to do, a more appropriate aim would have been, "How can we use a graph to determine the acceleration of an object?"
4. I indicated to you that giving a quiz or test that only contained one question was a poor way to evaluate understanding. Asking the students to solve a single problem would only tell you whether the students could do that particular problem. It wouldn't indicate their understanding of the concepts of motion, or even that they could solve a problem worded slightly differently. A student who understood the major concepts involved but couldn't understand the way the problem was worded would receive a poor grade, even
though they might be doing well with the material. The quiz or test should contain examples of problems but must also contain questions that test understanding of concepts. These might be in the form of multiple choice questions or open-ended questions. A question such as, "How could an object that is increasing in velocity have a constant acceleration" would illustrate understanding of the difference between velocity and acceleration.
A serious flaw in this lesson centered around your failure to provide students with an opportunity for feedback. You need to listen to their cries for help. When you present a problem's solution and then move on, despite complaints that students don't understand, they become frustrated and anxious. You have some of the brightest students in the school in your classes. These students are concerned that the grades they get will help them get into a good college, not hurt them. They want and need you to help them.
We discussed ways that you could provide for feedback within the lesson. One technique is to model a problem at the board and then assign each table a similar but slightly different problem to work on. After a reasonable amount of time, have a student volunteer from one or two tables explain their solutions to the class by coming to the board.
I will be returning to visit one of your classes again in the next week or two. I hope that you will begin to implement some of the suggestions we have discussed so that your next lesson can be rated as satisfactory.
Assistant Principal Supervision
I have received a copy and read this report. I
understand that a copy will be placed in my file.
David K. Roemer (signed)
September 28, 1994