kitchen table math, the sequel: talk and chalk

Monday, June 21, 2010

talk and chalk

from Have Technology and Multitasking Rewired How Students Learn? by Dan Willingham
When you encounter a new technology, try to think in abstract terms about what the technology permits that was not possible in the past. It’s also worth considering what, if anything, the technology prevents or makes inconvenient. For example, compared with a chalkboard, an overhead projector allows a teacher to (1) prepare materials in advance, (2) present a lot of information simultaneously, and (3) present photocopied diagrams or figures. These are clear advantages. However, there are also disadvantages. For instance, James Stigler and James Hiebert noted that American teachers mostly use overhead projectors when teaching mathematics, but Japanese teachers use chalkboards.33 Why? Because Japanese teachers prefer to maintain a running history of the lesson. They don’t erase a problem or an explanation after putting it on the board. It remains, and the teacher will likely refer to it later in the lesson, to refresh students’ memories or contrast it with a new concept. That’s inconvenient at best with an overhead projector.

33 James W. Stigler and James Hiebert, The Teaching Gap (New York: Free Press, 1999).

Having managed to follow most of Wu's lectures, I am a huge fan of this method - and a huge non-fan of the PowerPoint now-you-see-it, now-you-don't approach to teaching.

limits of working memory
working memory posts


lgm said...

I didn't know this style was considered Asian. My college profs all used it (engineering). Some rooms had 9 chalkboards; 3 rows of 3.

Powerpoint lectures seem to depend on the teacher's comments too much. Hard for middle and high school to take note and attach importance to certain comments at the right point in the presentation. We are batting 1 out o f 5 for middle & high school math teachers that can teach in teh "Asian" style such that the child's notes are sufficient reference for homework completion and the class presentation enables comprehension at the level that 'extra help' isn't needed.

Catherine Johnson said...

I didn't know this style was considered Asian.

Well - I don't know that the 'running history' approach is 'Asian' per se; I remember teachers using chalkboards this way, too.

Still, PowerPoint apparently has not supplanted the chalkboard in Asian classrooms. (Of course, Stigler's book is now 10 years old, right?)

PowerPoint is a terrible idea because of the severe limitations on working memory. There is no way a novice can hold the beginning of a lecture in mind all the way through to the end, which means students flipping back and forth amongst the PowerPoint pages (assuming they've been given a hard copy handout) or just giving up and losing the thread altogether.

A little while back, I read a book on ... public relations?? The author said you should NEVER hand out the hard copies of your PowerPoint precisely because of all the flipping back and forth that goes on.

Catherine Johnson said...

btw, I'm not intrinsically 'against' PowerPoint: bulleted lists are highly effective in terms of memory, learning, etc (I think).

BUT if a teacher is going to use PowerPoint, he or she needs to integrate it with a running-history on the chalkboard.

The PowerPoint should support the running history.

concerned said...

Thank you for the post! I wish I could have attended!

This is one reason that I like to use the smart board. [never was a fan of power points] With the smartboard, notes don't need to be erased and it's easy to go back and refer to something previously worked out - or even paste it into the current page. It's also nice to be able to use various colors for emphasis, and the notes, colors and all can be exported and sent (or posted) to students who were absent. Most absent students come back to class with their notes in hand, explaining how helpful they were and expressing their appreciation.

It has worked really well for me.

Catherine Johnson said...

that aspect of PowerPoints is *very* helpful, I agree

do you also have a running history on the blackboard?

do you hand out your PowerPoint hard copies before your lecture?

if so, do you have students doing a lot of flipping back and forth (i.e. is that a problem?)

Catherine Johnson said...

Where working memory is concerned, PowerPoints are an improvement over the overhead projector

CassyT said...

Since I was supposed to be helping to lead discussion at the MSMI2010, I had to read Wu's material and do the home enjoyment at least a day in advance. Because of this, I printed out the material single-sided and stuck it in a binder. Perhaps not the most eco-friendly thing to do, but I was able to take notes while Wu was talking, somewhat near the topics in the handbook.

Since each reading was 30 pages long, I was doing a lot of flipping to find the right spot, but my notes are now together, thereby triggering better long-term memory of the lesson.

Which is a good thing, because I think I blew out my long-term memory on day 2.

Note to self for future presentations: Right to left, right to left.

Catherine Johnson said...

I printed out the material single-sided

why didn't I think of that?

Catherine Johnson said...

because I think I blew out my long-term memory on day 2

oh, brother!

we were all at or beyond our limits about 90% of the time

without air conditioning, either!

Catherine Johnson said...

Perhaps not the most eco-friendly thing to do, but I was able to take notes while Wu was talking, somewhat near the topics in the handbook.

oh hell

that would be great

I've got a big blob of disorganized spiral notebook notes (interspersed with SAT practice problems) to sort through...

Catherine Johnson said...

the class presentation enables comprehension at the level that 'extra help' isn't needed

Wu is a master lecturer

listening to him, you see why the lecture format has been the classic mode of teaching demanding content

he asked lots of questions, too: very good rhythm back-and-forth between straight lecture, question-asking, and informal off-the-beaten track exposition and joking

this is an aspect of the lecture format people seem to have forgotten. Yes, there are professors who lecture straight for 50 minutes without asking or taking questions, a format that can work brilliantly. The Teaching Company is based in this format.

But there is a second lecture format that is far more interactive and varied amongst exposition, humor vs. seriousness, questioning of students, and built-in 'breaks' where the lecturer pauses to let students look over the board and think.

I found that often, at the point where my energy was flagging, Wu basically stopped the train. We didn't get off....but things slowed to a crawl and he repeated his last point several times in different ways while also making jokes.

He could keep the lecture momentum going when in fact we'd come to a halt.

Doug Lemov talks about this in Teach Like a Champion. His champion teachers all seem to maintain a very fast clip at all times -- BUT there are many times when they seem to be moving quickly but in fact they've stopped at one point the kids are clearly not getting. At that point they have numerous different ways of repeating the same content over and over until the kids **do** get it without seeming to be doing so.

Lemov calls this phenomenon 'pacing,' by which he means the **illusion** of speed - not actual speed.

Students have the illusion that they are zooming along even when they're not.