The Reflective Educator

Education ∪ Math ∪ Technology

Menu Close

Day: May 16, 2011

Don’t Lecture Me

Some highlights from the video above (thanks to @smartinez for sharing it):

  • Hardly anyone who teaches actually applies the scientific method to their teaching.
  • Most students are stuck on the Aristolian perspective of how physics works, learning real physics is incredibly difficult.
  • Disagrees strongly with Maslow’s hierarchy of needs.
  • Our old theories of learning haven’t been updated in 50 years. "We just accept them."
  • Lecture is the default teaching method at universities.
  • If you are going to do lecture, at least do it right. Increase the scale of the lecture, improve the skill of the lecturer. At least do it right.
  • If you have respect for the lecturer, your attention goes up, and your retention of what they say increases.
  • Hundreds of thousands of kids go through awful lectures each year.
  • Teachers ask too many pseudorhetorical questions, don’t give students enough time to respond, and students only ask an average of 2 questions a year.
  • Socrates often bullied his students into accepting his view of the world so the Socratic method is not all it is cracked up to be.
  • Lecture comes from "to read" as in reading a sacred text. "Preaching instead of teaching."
  • Feynman discovered that in Brazil students could learn from the book, but knew no physics. "Teaching through lectures is a hopeless task." ~ Feynman
  • "Data is not the plural of anecdote." ~ Eric Mazur
  • "Lecture is the transfer of the notes of the lecturer to the notebook of the student without passing through either." ~ Eric Mazur
  • Give the students the notes in advance. Seating arrangement matters. Lead your lectures through questions. Use feedback from your class to determine which way to go ahead. If majority of students are incorrect, have them discuss the ideas with each other.
  • "I’m just going to give it to you once, you have to get it right the first time." Lectures should be recorded since students will need multiple times to learn it.
  • What’s the point in recording lectures that were bad in the first place? Make sure the lectures are good.
  • Attendance at lectures is horrible.
  • Why don’t we worry about students not attending lectures? Why aren’t we doing something about it?
  • 25 minutes tops for attention span.

Here are ten fairly good points from his talk:

  1. Why are lectures 1 hour long?
    We based the length of lectures on scheduling, rather than on the attention span of the learner. 1 hour is itself based on the Babylonian time-system, and is extremely arbitrary as a result.
  2. Tyranny of time
    We have lots of ways of sharing our lectures whenever students want to access them, why do we force them to access them one time from a lecture hall?
  3. Tyranny of location
    Why do force people to attend something in person when they can’t interact anyway? If students could be involved in the discussion, then having them physically present makes sense, but otherwise, there is no particular reason they should have to come to the lecture hall itself.
  4. Psychological attention span
    People can’t focus for very long, particularly after a few days of lectures. We subject learners to class after class after class, when in fact their attention span cannot handle that much information to process.
  5. Cognitive overload
    Lecture crams too much information into a small amount of time. Students are forced to handle more information than they can handle, which is absolutely debilitating for learning.
  6. Episodic and semantic memory
    The mind doesn’t cope very well with the mixture of semantic (the processing of the content of the lecture) and episodic (from the processing of the visual) information you are receiving.
  7. Learn by doing
    Nothing in lecture gives students opportunity to engage with the material themselves. People learn loads from actually applying their knowledge.
  8. Spaced practice
    People need repeated practice over time, rather than one-off lectures. Lectures tend to give information and assume the learner will go and practice the information themselves, rather than allowing time for the learner to practice using the new knowledge immediately.
  9. Not collaborative
    Lecture isn’t at all collaborative. It’s probably not intended to be, but collaboration is an extremely effective way to learn, given the feedback you receive from your peers.
  10. Personality problems
    Teaching should not be the secondary job of a researcher. This is not a problem experienced in most K to 12 institutions, but is a serious problem at higher levels of education.

These are some pretty serious problems. What could you do to modify your practice? Should you lecture for an hour? I don’t think so. Instead, I recommend that you cut your lecture to only 10 minutes, on a small amount of material, and then give your students time to practice and engage with the material immediately.


Simulating transmission of knowledge in a classroom

I’ve created a simulation, which vastly over-simplifes classroom dynamics and information flow, in an attempt to look at some of the differences between a lecture style classroom and a cooperative learning classroom.

View this simulation here if you are having trouble seeing it above.

  • In a standard strict-lecture style classroom, the teacher does all of the talking, and the students listen. Each student independently tries to come to grips with the material, and there is a chance that they don’t understand it in the same way the teacher indends them. This corresponds to a student transmission level of 0 above, and any teacher transmission level.
  • In a mixed lecture and discussion setting, the teacher transmits most of the knowledge, but part of it is co-constructed with the kids in the form of a two way discussion about the material, wherein the students get clarification of what they don’t understand, and can ask questions. In this case, the students have a low transmission level, and the teacher transmission level is at any stage.
  • In a cooperative classroom, the students have a high transmission level, as they are free to mix and mingle with each other. What is not yet represented above (but will be as I work on this simulation) and I admit this is a problem, is the issue of students occasionally introducing misconceptions to each other, rather than the version of the truth that the teacher is hoping they will find. This corresponds to relatively high transmission rates for students and the teacher both (note: 50% is fairly high, given that this is intended to include a variety of factors).
  • The simulation also lets one choose a "flat" classroom where every student has the same ability, a normally distributed classroom, and either a skewed classroom toward a weaker or a stronger class. This choice affects both student transmission ability, and student "learning" ability.

Other than the obvious "you can’t simplify learning that much" comments, please give me some feedback on this system, and what other potential variables should be included. Please also play around with this simulation and explore the differences between the different classroom styles that you see.

Obama to students: You will need algebra

In his commencement speech ( story shared by @monsoon0 ) to a Memphis graduating class, President Obama said:

Through education, you can also better yourselves in other ways. You learn how to learn – how to think critically and find solutions to unexpected challenges. I remember we used to ask our teachers, “When am I going to need algebra?” Well, you may not have to solve for x to get a good job or be a good parent. That’s true. But you will need to think through tough problems. You will need to think on your feet. So, math teachers, you can tell your students that the President says they need algebra.

I really don’t get how solving for x in 3x + 17 = 5x + 2 will "help students think through tough problems [in life]" and "think on their feet." I see algebra skills as useful, but not out of context of the types of problems they help us solve. Instead of students learning an algorithm for which almost none of our students will ever get to see a real application; what if we taught students areas of mathematics which had direct application in their lives, and which actually helped them think?

I think that we do need some people who learn algebra in a really deep way, but the type of algebra that people use in their day to day lives is fairly simple, and doesn’t take very long to teach, especially if students see the value in what they are learning. Too long people have learned math because someone said they should. 

Well Mr. President, I don’t think that telling my students that just because you think it is useful will mean they will want to learn it. I’m going to keep focusing on presenting the mathematics I teach in the context of the lives of my students instead, thank you.

Newspapers have a purpose: They help us break free of “online filter bubbles.”

When I was watching Eli Pariser’s Beware Online Filter Bubbles TED talk, I wondered initially how one could work against this problem of the customization of the web. I thought to myself, wouldn’t be handy if there was a way to find an assortment of almost randomly aggregated content from a wide variety of interests.

I then remembered that newspapers are an aggregate of content from a wide variety of areas. Maybe they serve a purpose after all? Perhaps newspapers, at least some of them, should continue to focus on providing stories without bias that come from all over the world, from all walks of life. Not sure what the business model is, as most people seem to be content in their bubbles, but perhaps as Eli’s message is shared, they will be able to monetize their random access nature.