Test 1: BABBBADBCB
Test 2: BCDBED
Test 1: BABBBADBCB
Test 2: BCDBED
Just a note: I’ll be attending the International Conference on Technology in Collegiate Mathematics (ICTCM) in Chicago next week, March 12–14. I’ll be giving two short talks there:
I’m also going to be participating in the Geogebra workshop on Saturday in preparation for my junior/senior-level geometry course this fall.
I hope to do a lot of conference-blogging in the meanwhile, and I promise not to use the entire time as a pretext for bashing the TI N-Spire like I did back in 2008. If you’re coming too, let me know.
Friday music time again, and just about the only thing I’ve had time to post this week due to classes starting back:
Normally I would take one of the entries in the list that gets my attention and do a video focus on it. This time… Well, the classic Led Zeppelin chestnut “Living Loving Maid” (#9) makes me think of the fantastic cover done by Dread Zeppelin. You know — that band that does Led Zeppelin covers, only they’re done in a reggae style and using a late-70′s era Elvis impersonator as their lead singer. Sadly, I couldn’t find a video for that. So instead, here’s the video for their version of “Your Time Is Gonna Come”, which Robert Plant once said he preferred to the original.
It’s that time of the week again:
“Miracles Out of Nowhere” by Kansas (#7) is one of my favorite rock tracks. Here’s a live version (I can’t tell from where or when, but it looks recent):
That song is appropriate for today, too, since it’s my son’s first birthday. He was a surprise baby for us, so I’ll dedicate this song to him, our little “miracle out of nowhere”.
When I am having students work on something, whether it’s homework or something done in class, I’ll get a stream of questions that are variations on:
And so on. They want verification. This is perfectly natural and, to some extent, conducive to learning. But I think that we math teachers acquiesce to these kinds of requests far too often, and we continue to verify when we ought to be teaching students how to self-verify.
In the early stages of learning a concept, students need what the machine learning people call training data. They need inputs paired with correct outputs. When asked to calculate the derivative of , students need to know, having done what they feel is correct work, that the answer is . This heads off any major misconception in the formation of the concept being studied. The more complicated the concept, the more training data is useful in forming it.
But this is in the early stages of learning. Life, on the other hand, does not consist of training data. In real life, students are going to be presented with ambiguous, ill-posed problems that may not even have a single correct answer. Even if there is one, there is no authoritative voice that says definitively that their answer is right or wrong. At least, you’d have to stop and ask how you know that the authority itself is right or wrong.
So as a college professor, working with young men and women who most of them are one step away from being done with formal education, it serves no purpose — and certainly does not help students — to pretend that training, the early stage, goes on forever. At some point I must resist the urge to answer their verifying questions, despite the fact that students take great comfort in having their work verified for them by an external authority and the fact that teachers usually are perceived as being better by students the more frequently they verify.
I’ve started making the training stage and the self-verification stage explicitly distinct in my classroom teaching. In a 50-minute class, I’ll usually break down the time as follows:
I’ll spend the first 20 minutes of class focusing in on one or two main ideas for the class along with some simple exercises, a few of which I’ll do (to help students get the flow of working the exercises and to provide training data not only on the math but also on the notation and explication) and more of which they will do, providing full answers to the “Is this right?” questions along the way. Then five minutes for further Q&A or to wrap up the work.
But then the training phase is over, and students will get more complicated problems (not just exercises) and are told: I will now answer any question you have that involves clarifying the terms of the problem. But I will not answer any question of the form “Is this right?” or provide any guidance on technology use. What I will do instead, if students persist in asking “Is this right?”, is answer their questions with more questions of my own:
And so on. Many of these are merely ripped from the pages of Polya’s How to Solve It, which ought to be required reading of, well, everybody. In other words, in this post-training phase of the class, students must simulate life in the sense that they are relying only on their wits, their tools, their experiences, and their colleagues, and not the back-of-the-book oracle.
Also, by telling students up-front that this is how the classes are going to be structured, they get the idea that there is a time for getting verification and another time for learning how to self-verify, and hopefully they learn that the act (or at least the urge) to self-verify is something like a goal of the course.
My hope here is to provide training data of a different sort — training on how to be independent of training data. This is the only kind of preparation that makes sense for young adults heading for a world without backs of books.
* You could make a good argument that Wolfram|Alpha used in this way is just a very sophisticated “back of the book” — an oracle that students use as an authority. I think there are at least a couple of reasons why W|A is more than that, and I’ll try to address those later. But you can certainly comment about it.
This report Frinom the Atlanta Journal-Constitution, citing an article in the June 1 Proceedings of the National Academy of Sciences, says that differences between boys’ and girls’ performance on standardized mathematics tests correlates with the level of gender equity and other socio-cultural factors in the country in which the test was taken.
The study’s co-author says:
“There are countries where the gender disparity in math performance doesn’t exist at either the average or gifted level. These tend to be the same countries that have the greatest gender equality,” article co-author Janet Mertz, an oncology professor at the University of Wisconsin-Madison, said in a university news release.[...]
“If you provide females with more educational opportunities and more job opportunities in fields that require advanced knowledge of math, you’re going to find more women learning and performing very well in mathematics,” Mertz said.
The study goes on to cite the US as a country where there is a relatively high degree of gender equity and hence a relatively equal performance on standardized tests between boys and girls, with more and more girls taking advanced courses in science and math. But, importantly, the study also warns that
“U.S. culture instills in students the belief that math talent is innate; if one is not naturally good at math, there is little one can do to become good at it,” Mertz said. “In some other countries, people more highly value mathematics and view math performance as being largely related to effort.”
This is a point well worth noting. What will it take for the culture in the US to get away from the idea that you’re either born with mathematical ability or born without it — in other words, mathematical predestination?
On Twitter right now I am soliciting thoughts about calculus courses, the topics we cover in them, and the ways in which we cover them. It’s turning out that 140 characters isn’t enough space to frame my question properly, so I’m making this short post to do just that. Here it is:
Suppose that you teach a calculus course that is designed for a general audience (i.e. not just engineers, not just non-engineers, etc.). Normally the course would be structured as a 4-credit hour course, meaning four 50-minute class meetings per week for 14 weeks. Now, suppose that the decision has been made to cut this to TWO credit hours, or 100 minutes of contact time per week for 14 weeks.
Questions: What topics do you remove from the course? What topics do you keep in the course at all costs? And of those topics you keep, do you teach them the same way or differently? If differently, then how would you do it? Finally, would there be anything NEW you’d introduce in the course that would be pertinent for a 2-hour course that wouldn’t show up in a 4-hour version of that course?
Keep Twittering your comments to me at @RobertTalbert, or comment below. I’ll sum them up later.
UPDATE: I also meant to say, feel free to play with the assumptions I am making here. For example, if it’s impossible to think of a 2-hour calculus course, change that to a 3-credit course and see if you can come up with anything.