How many times have you been surprised by how little of a textbook chapter you remembered when you finished reading it? Can't recall, but you're guessing the answer's somewhere between "often" and "every"?
You'll be relieved to know that you're in good company if your memory power's not . . . well, memorable. On the average, students remember only about half of the main points they read when they've just completed a typical textbook chapter. Then, of course, unless they review the material, their memory of that half becomes foggy pretty quickly — not a good formula for test success!
One reason that students remember so little is that they often read through a textbook without stopping now and then to process the information. (Process means doing something — anything — to mesh the information into memory.) If you do nothing within the first 20 seconds to hang on to a new piece of information, you will usually forget it. (For example, 20 seconds after someone tells you a phone number, you probably can't repeat the digits unless you've tried in some way to "capture" the numbers in your head.)
Okay, you may say, "But I do remember some things I read or hear without 'doing' anything with them." Most likely, in these cases, either the new information has a special significance for you or you unconsciously associate it with something you already know about the subject.
Here's an example of an unconscious association: In a world history text you read, "War was the focus of life for the Spartans. They practiced extreme self-denial to become more effective soldiers." If you're aware that the word Spartan means "self-denying," you might associate the new information with what you already know.
Multiple coding means that if you fix something in your memory in more than one way, you are more likely to remember it. Take the case of the Spartans. One way you could "code" is to relate the new information to a definition of the word. If you also remember a movie you've seen that shows Spartans in military mode, that's a second coding. Every coding you keep in mind brings you closer to retaining the information long term.
Before you go coding crazy, step back and do the obvious: Decide what you want to remember.
Everybody's seen the students who highlight just about every sentence on the textbook page. These students are saying, in effect, that everything is important (or that they can't tell the difference).
Like a person trying to buy too much with a limited paycheck, these students are spreading their mental energies too thin. Trying to remember every detail of every class can lead to frustration and failure (unless you have set all your spare time aside for studying and enjoy doing nothing else).
At the other extreme are students who rarely mark anything on a page, possibly because they assume that little is worth noting. The instructor, however, is likely to think differently about the material and, after all, he or she is the one creating the exam.