Tuesday, August 2, 2011

[WDIDWT] When do I do with this? Lecture Edition


Folks, it's a joke. Just ignore it and move on to the post.

I'm hoping that this will be the first in a series. One of the things that I'm struggling with right now is that I don't have a good sense for when the various instructional strategies are appropriate.

When do I lecture?
When do I have students explain ideas to each other?
When do I assign a worksheet?
When do I have students solving an application problem?
When do I question with the entire class?
When do I have the class look for procedural mistakes?

Feel very, very free to leave your thoughts in the comments.

I'm going to start with lectures, since it's what I spend most of my time doing in the classroom. (Scorn! Scorn!)

 First, though, I suppose we should define what it means to lecture. For various reasons (explained here), I think that it's helpful to take the word "lecture" to essentially mean "explaining." I take lecturing to be a specific flavor of explaining -- lecturing to me is explaining something to a larger audience. Clearly, sometimes explaining is a good way to help a person learn new information. After all, we spend much of our communication with others explaining things. The question is, how should it work in the classroom?

When should I lecture?

Here's a neat little summary of some papers that I found on a neat little website:

Johnson, et. al (1991) and Bonwell and Eison (1991) highlight several uses where lectures are appropriate:
  • To disseminate information to a large number of people in a short period of time.
  • To present concepts too difficult for students to process on their own.
  • To gather information from a variety of sources that may take the students a long time to gather.
  • To arose interest in the subject.
  • To teach auditory learners.
  • To present information unavailable to the public such as original research. 

This list rings true with me. But even when lecture is appropriate, it needs to be used carefully.
"Research shows that students listening to a 50-60 minute lecture are unable psychologically or physiologically to concentrate on the content and retain it. One study found students could recall 70% of the content from the first 10 minutes of the lecture but only 20% from the last 10 minutes (Hartley and Davies, 1986)"
Lesson: don't lecture for long. Combine that with the unique capacity of verbal communication to inspire and captivate, and there's a strong case for starting each lesson with a short lecture that does some of the following things:
1. Motivates the content.
2. Provides necessary background information.
3. Takes a first pass at explaining a concept.

The trickiest thing is the third, though. A lecture should hit as many people as possible with a concept, but it's crucial that students not feel as if they understand the entire concept from the lecture. This is a subtle thing, but if you lead off with an explanation, that's going to feel like learning to the student, and make it harder to follow up with instructions that aims to deepen that knowledge. That's probably more something to be aware of for introducing those sorts of activities, rather than lecture, though. Lecture can't be the whole story, but there's no reason to force it to do less than it's capable of. That's just being silly.


In summary:
1. Lectures are good at arousing interest in a subject. It's good to lead with that.
2. No reason not to try to hit as many people with the hard/essential/fundamental concept of the day with the lecture. Just make sure that you follow that up with an activity that takes a second pass at this concept, and make sure that you don't allow students to convince themselves that lecture gave them all that they need. (Try, asking a question whose answer is a straightforward, but unintuitive, consequence of the new concept).
3. Don't lecture for long without breaking it up with some sort of pause procedure.

Sources: (will hopefully update this as I discover more sources)
1. http://www.wcer.wisc.edu/archive/cl1/cl/doingcl/lecture.htm 
2. http://blog.mrmeyer.com/?p=10652#comment-291577

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