CLOSING THE HOLES ON SWISS CHEESE KNOWLEDGE

Over the years, I have argued often on this blog that one of the really weak spots in education was the failure of students to close the holes on what I call “Swiss Cheese Knowledge.”   Thus, on the first day of class last week, I drew a block on the board and put holes in it.  I then explained the drawing to my students.

When you leave class every day, your knowledge looks like a block of Swiss cheese.   It appears entirely solid.  However, it is full of holes—things you missed, things you misunderstood, things you did not quite catch.  I know the knowledge feels solid, but it really is not.   If you do not take action, those holes just get bigger as time passes and your memory begins to fade.   Having taught for nearly 50 years, I know where the holes are likely to be.   I can and will write test questions to expose those holes.  In many ways, testing is just an attempt to measure the quantity and size of the holes in your knowledge.  

How well you do in this course is very much dependent on what you do after each class to close those holes before they simply get too big to manage.  I think this is the part of learning that most students either do not appreciate or simply choose to ignore.   You have to close those holes in your knowledge or I will find them on the tests.  Then, you will come to me after the test and say, “I knew the material perfectly until the test started and then I just froze and couldn’t answer any of the questions.”   No, that is a popular student story but it is rarely true.   The knowledge looked and felt solid to you but it was really full of holes and I found them.

There are many things you can do to close the holes but I want to suggest two.   First, I will send you practice exercises throughout the semester that will begin, “Here is a practice question based on what we covered today in class.   I wrote it so you could determine if you had any holes in your knowledge.  The answer is X.   If you get that answer, then move on.  I am not worried about you.   But if you cannot get X, come by and see me, sooner rather than later.  We need to fill in that hole.”

The second thing takes more discipline.   As soon as possible after class, write out a memo on everything we covered today.  Assume you were writing the memo to a friend who missed class and needs to know what we covered in a very clear and organized way.   Class moves very quickly and has a helter-skelter feel to it.   Nevertheless, if you look closely, you will begin to realize that there is a fairly well defined organizational structure.   By writing out a “friend memo,” you’ll start seeing the whole picture.   That’s a good way to start noticing some of those holes in your knowledge so that you can take action.

From my experience, students are good about doing practice questions because they are curious as to what I thought was important and whether they can do it.  Writing “friend memos,” though, is tougher.   It is not as much fun and takes some time.  As one student said, “That much thinking makes my head hurt.”

So, the holes are never filled.

I think we often fail to realize how much guidance our students need.   We can tell them but, in most cases, we need to show them as well.   For example, during the second day of class, we spent the entire 50 minutes talking about a lot of liability questions – Why is this a liability?   Why is that not a liability?

Immediately after that class, I wrote out a detailed memo and sent it to the students.  “It might not have seemed like we covered much today and it might have all seemed rather random but here’s exactly what we did.   We covered a whole lot of material.”   I very much wanted to show them exactly what a class memo could look like.  They need that modeling.  I cannot over emphasize that one sentence.

I will not do that again this semester.   I wanted to do it once to show them what I meant.   I have made my point.   Now, it depends on them if they have the ambition needed to do the work.  I felt like I needed to impress on them the problem of Swiss Cheese knowledge and two important steps needed to fill in those holes.

I think teachers often think all learning problems originate during class.   I am much more inclined to believe that many if not most problems happen in the day or so immediately following class.   That is why I focus so much attention on that time period.