Tag: textbook

Motivation for pre-reading assignments

Image: chain by pratani on flicker (CC)

For the next 4 months, I’ll be working with an instructor in an 4th-year electromagnetism course. If you’ve taught or taken a course like this, let me just say, “Griffiths”. If you haven’t, this is the capstone course in E&M. It’s the big, final synthesis of all the electricity and magnetism and math and math and math the students have been accumulating for the previous 3-1/2 years. This is where it all comes together and the wonders of physics are, at last, revealed. It’s the course all the previous instructors have been talking about when they say, “Just learn it. Trust me, it will be really important in your future courses…” That’s the promise, anyway.

The instructor came to us (“us” being the Carl Wieman Science Education Initiative) because he wasn’t happy with the lecture-style he’s been using. Students are not engaging, if they even bother to come to class. He’s trying to use peer instruction with clickers but it’s not very successful. He wants to engage the students by giving them worksheets in class but he’s not sure how.

So much enthusiasm! So much potential! Yes, let’s totally transform this course, flipping it from instructor- to student-centered! Yes, and I purposely using the word “flipping” with all its baggage!

Hold on there, Buckaroo! One thing at a time. Changing everything at once rarely works. It takes time for the instructor to make the changes and learn how to incorporate each one into his or her teaching.

So, we’re tackling just a few things this term. The first is to create learning goals (or objectives) so we can figure out how to target our effort. In talking with the instructor, I learned there are very few new, mathematical techniques introduced in the course. Instead, the course is about selecting the right sequence of mathematical tools to distill fundamental physics out of the math describing E&M. That led us to this draft of one of the course-level, big-picture goals:

While you are expected to remember basic relationships from physics like F=dp/dt and λ=c/ν, you do not have to memorize complicated formulas we derive in class because a list of formulas will be given. Instead, you will be able to select the applicable formula from the list and know how to apply it to the task you’re working on.

The biggest change we’re making is the introducing effective pre-reading assignments. Oh sure, the instructor always said things like “Pre-reading for Lecture 1: Sections 12.1.1 – 12.1.3” but that’s not doing the trick. More and more of my colleagues are having success with detailed, targeted reading assignments. Rather than the “read the whole thing and learn it all” approach, we’re going to help the students learn (ha! Imagine that!):

Reading assignment (prior to L1 on Thu, Jan 10)
==================

Read Section 12.1.1. Be sure you can define an "inertial reference frame"
and state the 2 postulates of special relativity.

Review Section 12.1.2 (these concepts were covered in previous courses)
especially the Lorentz contraction (iii) and write out the missing steps
of algebra at the top of p. 490 that let Griffiths "conclude" Eqn (12.9).
Be sure you can explain why dimensions perpendicular to the velocity are
not contracted.

Read Section 12.1.3. Look carefully at Figure 12.16 so you're familiar
with the notation for inertial frames at rest (S) and inertial frames in
motion ( S with an overbar )

Now comes the hard part: getting the students to actually do it. It’ll take effort on their part so they should be rewarded for that effort. A reading quiz, probably in-class using clickers, worth marks could be that reward. (An online quiz we can use for just-in-time teaching might be even better but one thing at a time.) A straightforward quiz-for-marks promotes sharing answers (that is, cheating) and clicking for students not there (that is, cheating). I don’t want them to participate for that sole reason that they’ll be punished for not participating. I’d rather use a carrot than of a stick.

How do we present the pre-reading assignment as something the students WANT to do? Here’s a chain of reasoning, developed through conversations with my more-experienced colleagues. It’s addressed to the students, so “you” means “you, the student sitting there in class today. Yes, you.”

link 1: Efficient. You have a very busy schedule full of challenging courses. You want to use your E&M time efficiently.

link 2: Effective. We want the time you have allocated to E&M to be effective, a good return on your investment.

link 3: Learning. We recognize that many of the concepts will be learned when you do the homework. But rather than using class time to simply gather information for future learning, what if you could actually learn in class? Then you’d better follow along in class and you’d already be (partially, at least) prepared to tackle the homework.

link 4: Engagement. We’re going to create opportunities for you to learn in class through engaging, student-centered instructional strategies. But you need to be prepared to participate in those activities.

link 5: Preparation. To try to ensure everyone has neighbours prepared to collaborate and peer-instruct, we’re asking you to complete the pre-reading assignment. It will also save us from wasting valuable class time reviewing material that some (most?) of you already know.

link 6: Reward. This takes some effort so we’re going to reward that effort. If you do the readings as we suggest, the reading quiz questions we ask will be simple, a 5-mark gimme towards your final grade. Oh sure, you’ll be allowed to miss X of the quizzes and still get the 5%. Those marks are for getting into the habit of preparing for class, not a penalty for being sick or not being able to come class. The quizzes are also continuous feedback for you: if you’re not getting 80% or more on the reading quizzes, you’re not properly preparing for class. Which means you’re not link 5, 4, 3, 2, 1.

The big message should be, your effort in the pre-reading assignments will help you succeed in this course, not just with a higher grade but with better grasp of the concepts and fewer all-nighters struggling with homework.

Is it all just a house of cards? I don’t think so. And I’ll find out in the next few weeks.

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