A lecturer who is speaking and writing on a chalkboard (or equivalent) usually knows the lecture well and is writing to emphasize and explain key points.
A lecturer who is using PowerPoint often does not know the lecture well, and is trying to hide behind the slides or use them as notes to remember what to say.
Both may be experts about the domain they are discussing, but much more often the chalkboard presenter knows the lecture being given.
The best lectures I've seen have powerpoint & chalkboard, sometimes with an overhead projector. Each have their purpose.
1. For displaying text, graphics, animations, etc a powerpoint presentation is great.
2. The chalk board is great for pulling out important equations that will be used throughout the lecture (not lost on slide changes) and to interactively work through a problem. You can draw something out and then ask students what to do next and then execute.
3. Overhead slides are great to manipulations on complex forms. For instance showing how a parser works on a piece of text you can use a pen to mark up the text. Or to show how different actions can effect a system. For instance if we increase the interest rate, the line moves like this etc. This allows you to answer questions in real-time in a visual way.
I see some professors use pen tablet input on computer slides during a lecture. This is similar to what you describe for overhead slides. In practice, they also seem to use it for the things you describe for the chalkboard.
My favorite video lectures are Gilbert Strang teaching Linear Algebra with nothing but a piece of chalk and a whole lot of chalkboards (the kind that slide up and down, revealing other chalkboards underneath). I can't think of any way those lectures could be improved by any sort of technology.
I honestly think this is related to the ideas in Edward Tufte's "Cognitive Style of Power Point: Pitching Out Corrupts Within" [1]. I've had professors who used PP elegantly, but, anecdotally, their methodology was far different. I'd speculate that PP simply doesn't have the information capacity to truly cover complex material.
If a professor understands this, they can use it effectively as a skeleton of a lecture which persists aiding students' intuition of the hierarchy of the material. If a professor, who may well understand the material, doesn't catch the information dearth of PP, they often only end up presenting a small part of the material.
I have met a few people who use Keynote (PowerPoint eqv for OS X) who spend a lot of time refining their slides, animations, and embedded multimedia to get the perfect lecture. I would imagine they would do fine at the chalkboard, but seem to want to be in a "perfect message" kick.
From my experience it really depends on the class that you are taking. If the class relies heavily on images that cannot be easily drawn or represented and needs little textual content to achieve ideas PowerPoint presentations can really work well.
When you have subjects like mathematics and physics purely chalkboard whiteboard lectures is the only thing that works, even classes that are based heavily on either really need a chalkboard.
A mix can work well when the lecturer needs to represent a large amount of diagrams and concepts but still needs to explain how to work out complicated concepts, like example problems. (This is usually where the lecturer really knows a subject.)
I don't believe that Maths or Physics can really be taught using the traditional lecture format. The lecture may suffice to run through the techniques of various proofs, or tell the student what he/she needs to learn. The only way really to learn these technical subjects is to sit down with a pencil and paper and do it through. The same is true for Computing Science. Until you run through the examples and derive/write things for yourself, you'll never truly understand them, regardless of the format of a lecture, or the capability of the teacher.
For what it's worth, I have a degree in Maths, a PhD in Physics and I am develop software for research purposes, when I don't teach - so I have some experience.
The best way for a student to learn these hard technical subjects is for them to sit with their colleagues and go through group exercises, alongside a lot of hard individual work. The teacher's job is merely to help them over the hurdles they have difficulty with, and to show them the things that are truly worth learning. Although I never went through it myself, I suspect that the Oxbridge system of having indiviual tutoring sessions in small groups as the basis of the teaching is probably perfect for these purposes.
The Oxbridge system relies heavily on lectures to set the scene for the group supervisions though. You only get one or two hours of small group tuition per week per topic, so you need to make the most of it. The system generally goes: go to lectures to be introduced to the core concepts in play, have a sheet of 10-20 example questions to work on per week, bring as much of the questions as you can do to your supervision and go through the correct forms. In between we generally worked in peer groups to make sure we had enough to bring to the supervisions in the first place.
Agreed. I teach 60-minute classes using both a chalkboard and 15/20 slides prepared with Latex and Beamer -- http://en.wikipedia.org/wiki/Beamer_(LaTeX) -- which I post on my course page in advance for to the students to print and use in class.
Slides are useful for many reasons (diagrams that need many colors, animations, etc.) and the chalkboard is useful for answering students' questions and giving more examples if needed. I don't think I could teach well without either of them.
Comments
In my experience:
A lecturer who is speaking and writing on a chalkboard (or equivalent) usually knows the lecture well and is writing to emphasize and explain key points.
A lecturer who is using PowerPoint often does not know the lecture well, and is trying to hide behind the slides or use them as notes to remember what to say.
Both may be experts about the domain they are discussing, but much more often the chalkboard presenter knows the lecture being given.
The best lectures I've seen have powerpoint & chalkboard, sometimes with an overhead projector. Each have their purpose.
1. For displaying text, graphics, animations, etc a powerpoint presentation is great.
2. The chalk board is great for pulling out important equations that will be used throughout the lecture (not lost on slide changes) and to interactively work through a problem. You can draw something out and then ask students what to do next and then execute.
3. Overhead slides are great to manipulations on complex forms. For instance showing how a parser works on a piece of text you can use a pen to mark up the text. Or to show how different actions can effect a system. For instance if we increase the interest rate, the line moves like this etc. This allows you to answer questions in real-time in a visual way.
I see some professors use pen tablet input on computer slides during a lecture. This is similar to what you describe for overhead slides. In practice, they also seem to use it for the things you describe for the chalkboard.
My favorite video lectures are Gilbert Strang teaching Linear Algebra with nothing but a piece of chalk and a whole lot of chalkboards (the kind that slide up and down, revealing other chalkboards underneath). I can't think of any way those lectures could be improved by any sort of technology.
That's a great combined usage of those three tools.
I honestly think this is related to the ideas in Edward Tufte's "Cognitive Style of Power Point: Pitching Out Corrupts Within" [1]. I've had professors who used PP elegantly, but, anecdotally, their methodology was far different. I'd speculate that PP simply doesn't have the information capacity to truly cover complex material.
If a professor understands this, they can use it effectively as a skeleton of a lecture which persists aiding students' intuition of the hierarchy of the material. If a professor, who may well understand the material, doesn't catch the information dearth of PP, they often only end up presenting a small part of the material.
[1] http://www.edwardtufte.com/tufte/books_pp
I have met a few people who use Keynote (PowerPoint eqv for OS X) who spend a lot of time refining their slides, animations, and embedded multimedia to get the perfect lecture. I would imagine they would do fine at the chalkboard, but seem to want to be in a "perfect message" kick.
From my experience it really depends on the class that you are taking. If the class relies heavily on images that cannot be easily drawn or represented and needs little textual content to achieve ideas PowerPoint presentations can really work well.
When you have subjects like mathematics and physics purely chalkboard whiteboard lectures is the only thing that works, even classes that are based heavily on either really need a chalkboard.
A mix can work well when the lecturer needs to represent a large amount of diagrams and concepts but still needs to explain how to work out complicated concepts, like example problems. (This is usually where the lecturer really knows a subject.)
I don't believe that Maths or Physics can really be taught using the traditional lecture format. The lecture may suffice to run through the techniques of various proofs, or tell the student what he/she needs to learn. The only way really to learn these technical subjects is to sit down with a pencil and paper and do it through. The same is true for Computing Science. Until you run through the examples and derive/write things for yourself, you'll never truly understand them, regardless of the format of a lecture, or the capability of the teacher.
For what it's worth, I have a degree in Maths, a PhD in Physics and I am develop software for research purposes, when I don't teach - so I have some experience.
The best way for a student to learn these hard technical subjects is for them to sit with their colleagues and go through group exercises, alongside a lot of hard individual work. The teacher's job is merely to help them over the hurdles they have difficulty with, and to show them the things that are truly worth learning. Although I never went through it myself, I suspect that the Oxbridge system of having indiviual tutoring sessions in small groups as the basis of the teaching is probably perfect for these purposes.
The Oxbridge system relies heavily on lectures to set the scene for the group supervisions though. You only get one or two hours of small group tuition per week per topic, so you need to make the most of it. The system generally goes: go to lectures to be introduced to the core concepts in play, have a sheet of 10-20 example questions to work on per week, bring as much of the questions as you can do to your supervision and go through the correct forms. In between we generally worked in peer groups to make sure we had enough to bring to the supervisions in the first place.
Agreed. I teach 60-minute classes using both a chalkboard and 15/20 slides prepared with Latex and Beamer -- http://en.wikipedia.org/wiki/Beamer_(LaTeX) -- which I post on my course page in advance for to the students to print and use in class.
Slides are useful for many reasons (diagrams that need many colors, animations, etc.) and the chalkboard is useful for answering students' questions and giving more examples if needed. I don't think I could teach well without either of them.
This is it exactly. I mean to update the post to include this point, if you don't mind.