NOTES MAKING METHOD

You do not go to class to get a good set of notes. It is hardly worth spending several hours a week for a whole term to get information that can be bought for a few dollars in the form of a good reference book. The prime reason for your going to class is to learn something. In taking notes, keep this thought in mind. Do not overemphasize the notes to the extent that you neither see nor hear the lecture.

Taking good notes in a physics lecture is quite different from taking good notes in, say, a history class. One of the main differences is that most history lectures are largely the presentation of factual historical material, whereas most physics lectures are primarily the explanation of a comparatively small number of principles. These usually are illustrated by examples and by demonstrations. Outline form is good in history because it may be impossible to write down all the facts as rapidly as they are given to you, but if you use outline form in physics, at the end of a lecture you have only a portion of a page of notes, and probably they are not very illuminating. Outline form is unsuited to physics because in an outline you will not get down enough of the explanation to help you much afterwards. For explanation put down complete sentences (subject, predicate, object, etc.) but abbreviate long words. If you expect to be able to ‘decode’ your notes later, do not omit important words whether they be verbs or prepositions, In physics it makes a lot of difference whether a force is exerted by one object on another, or vice versa. To illustrate, on the subject of the ballistic pendulum the professor explains: “The kinetic energy of the bob at the bottom of its swing is equal to its potential energy at the top of its swing. Therefore from the height to which the bob swings, one can calculate what its velocity was at the bottom of the swing, in the following way....” The good note-taker writes: “KE of bob at bottom of swing = PE at top. :. from height bob swings can calc vel at bottom thus...”

Diagrams or formulas are put on the board. Actually they are the least important things to put in your notes, since they can be found afterwards in the text. The main thing to record is the explanation that accompanies them. (You will understand the explanations better if you spend some of your time studying before class.) If a diagram is labeled on the board, be sure to put down all of the labels. Three arrows coming from a point may mean nothing in your notes but, if they are accompanied by several sentences of explanation and by appropriate labels on the diagram, they may show the complete story of the forces acting on some point of a complicated structure such as a cantilever bridge, or they may show something simpler, thus:

The professor says (and draws the diagrams):

“A picture frame hangs from a hook in the ceiling C by two strings A and B, each making an angle of 30° with the horizontal. There are three forces acting on the hook, the upward pull F_C exerted by the ceiling, and the two downward forces F_A and F_B due to tensions in the strings A and B. Since the hook is at rest, it must be in equilibrium, and we may apply the force-polygon method to determine the relationships among the various forces...”

You copy the diagrams and write:

“Picture hangs from hook. Forces acting on hook are upward pull F_C exerted by ceiling and downward pulls F_A and F_B exerted by strings. At rest :. equilibrium :. polygon method....”

Probably the professor will show how F_A, F_B and F_C are related and then go on to discuss the forces acting on the ceiling or the forces acting on the picture frame, none of which has been mentioned yet.

One of the most deflating experiences a professor can have is to examine the notes taken by students in his classes. In the example above, the professor probably puts nothing on the board except the diagrams (writing many sentences on a blackboard makes a dull lecture) and some students’ notes consist of nothing but the diagrams. The important ideas, however, are in the application of the principles to the specific problem represented by the diagrams. In other words, the explanation that accompanies the diagram is the most important part of the discussion and the student—if he takes any notes at all—should put the explanation in his notes. If the instructor goes too fast, ask him a question to slow him down; for example, “Would you state that conclusion again, please?”

For most students, two to four pages of notes is a reasonable amount for one physics lecture, Do not ignore the demonstrations. Draw a diagram of the experimental setup and tell what principles are illustrated. If you don’t know what the demonstration is supposed to demonstrate, ask the instructor.

If the lecturer follows a text rather closely, study the book before class, take it to class, keep it open, and make notes in the margin or on a separate sheet of paper.

Some students find it better to take no notes at all during lecture (or to take very sketchy ones) and to spend the full time concentrating on what is being said without being distracted by frantically trying to write everything down. Immediately after lecture, they write out a complete set of notes (with detailed explanations), using the text (and their sketchy notes, if any) to aid them in remembering what was discussed.

Sometimes students pair off, one of them concentrating on getting good notes (making a carbon copy) and the other concentrating on digesting the explanation. After class they discuss the lesson together. While this procedure has something to recommend it (especially in advanced courses), it puts too much emphasis on the importance of notes.

Psychologists say that the physical operation of writing a set of notes contributes something to the learning process, in addition to the fact that the material being written almost of necessity has to have made some mental impression. Therefore you must have at least one set of notes in your own handwriting. This set ought to serve the double purpose of being a learning aid physically, as well as helping in review. Consequently, whether or not you take notes in lecture, when the lecture is over your note work has only begun. While the material is still fresh in your mind (preferably within a few hours after lecture), go over your notes and smooth them out. Add to the explanations. Compare the lecture with the text and fill in the parts you missed. If the material still seems obscure, consult another text in the library. Pick out the important statements in the notes and the important formulas; then underline them with red pencil to facilitate your review for exams. It is likely that in a whole term’s work there will be fewer than twenty important formulas you must know. But remember it is the method of applying them that really counts.