In general, students tend to learn and retain more, and enjoy the learning process more, when they are hole filling. In your own life, you probably have more fun when you learn something on your own by reading, asking questions, and discovering the material, than when you memorize the same material for no apparent reason.
I recently had an interesting hole filling experience while working with a student in my office. Curt had come by for some debugging help on a piece of code he had written, and we were editing the code on a Macintosh computer.
When editing any document on a Macintosh, as everyone knows, the document appears in a "window" on the screen. On the right side of the window is an area called a "scroll bar" which consists of two arrows that are used to scroll through the document; a gray shaft used to page through the document; and a white box used to jump instantly to any point in the document. The white box also shows your relative position in the document.
Using the mouse, you can move the white box to the bottom of the scroll bar, and when you do this you are instantly taken to the bottom of the file. The whole process takes about half a second. When Curt saw me do this, his comment was, "Oh, that's how you do that!"
Curt had a small hole in his knowledge. He had been using an inefficient technique to get to the bottom of his files for several weeks, and was looking for a better way. He had never remembered to actively ask a question about this hole, but he was alert and ready to notice the answer the moment he saw it.
One interesting thing about this little learning event is, if the hole hadn't been there, Curt never would have noticed what I was doing. If he had never needed to go to the end of a document quickly, it would have gone right over his head. If he already knew how to do it, he would have ignored it. People tend not to notice things unless they need them.
What happened in this exchange of information? Curt was the student, but he was doing nothing we normally associate with "studenthood." He was not sitting in the library, or reading a text book, or memorizing material important for a test. The piece of knowledge was never written on a blackboard nor in his notes. Yet the piece of knowledge was learned instantly, and is likely never to be forgotten.
If students have many small holes that they are filling in this way as they listen to your lectures, you can make regular use of this process. This hole filling process can also make lectures more interesting and important to students.
The previous example demonstrates one type of hole filling. Small holes in student knowledge can be filled by single questions or simple examples, providing details that fill out a subject or make life easier for the student.
It is also possible to create larger holes. For example, a student came by my office several weeks ago to ask a question about a homework assignment in another class. The solution to the problem relied on a subject area called graph theory. It involved fairly simple, straightforward graph theory techniques, but the student would have to learn the basics of the area to find the techniques and then understand their application.
He went to the library, checked out a book, read it, worked through the problem, and found a related solution. In a day the student learned material that might have taken a week of class time to present. This spurt of activity was caused by a rather large hole (one that to me seems too large - see below) that the student needed to fill in order to solve a problem. In addition, the material was learned voluntarily, and will probably be retained far longer than if the student had simply memorized "graph theory principles" for the sake of a test score.
In order to create knowledge holes for your students, remember three things:
It is often useful to create problems that contain a small hole in the middle. Students can then get started, see where they are going, stop and successfully fill the hole, and then wrap up the problem.
Another way to create holes with homework is to give a standard assignment, and then have a final problem that is defined as "needed to get an 'A'." Students are able to work on the other problems using standard techniques, but to answer the final problem they have to do some research or hole filling. Remember that this final problem won't be effective unless it 1) creates a need by being interesting, 2) can actually be filled by a normal student, and 3) is supported by the material needed to fill the hole(s) created.
When students fill knowledge holes, they are acting as self-motivated learners. As they progress through their college careers, students should be encountering, or seeking on their own, more and more experiences involving hole filling.
One way to expose students to the research process is to expose them to your own research. Several ideas that might help you do this in your classes follow.
Recently I sat in on a class where the professor devoted an entire lecture to his current research problem. He explained the problem and then went into the solution being developed. He also introduced work done by others in the field and showed how their solutions were being either applied or ignored. He explained some of the new ideas that have been developed and discussed their advantages and disadvantages. You might consider presenting a lecture like this, devoted to one or two of your current research topics, with the goal of showing students the research process and why you find it stimulating.
Recently I left the question, "Why do we perceive this as a house?" with a picture of a house below it, on the white board in my office. This question is important to research in perception. A student came by my office and asked about it. Soon four of us were discussing this question, and we carried the discussion into the classroom. Students were very interested in this question, and brought a number of interesting ideas to bear on it from art, psychology, etc. Try bringing active research questions, processed so that they are graspable by students, into the classroom.
Finally, when you introduce a new technique in class, consider finding and copying the original article on the technique and giving it to the class. This will let students see that a normal human being originally conceived the idea as part of his or her research.