An Innovative Approach to Teaching Undergraduate Particle Physics

Course Design Recommendations

Introduction

What constitutes good course design in a given setting depends on many things: the number of students in the class, their characteristics and background, the instructor’s capabilities and experience, the institution’s culture of expectations and so on. In what follows, I (the author) will provide some suggestions about the design principles and methods for realizing those principles that have worked for me, but instructors will probably need to adjust the details to fit their particular settings.

Pacing

Each chapter in this text has been designed to comprise a logical unit of roughly the right length to be covered in a single 75-minute class session. In a course where one has two such sessions a week, one can therefore hope to discuss roughly 26 to 28 of the 32 chapters in a typical 14-week semester.

The text thus has more chapters than one can likely cover in one semester. This was intended to allow an instructor to choose a pathway through the text that best fits the students’ background and needs. The book’s preface provides a good introduction to how the chapters depend on each other, but follow this link to explore some sample pathways.

If a course has three 50-minute class sessions/week instead of two 75-minute sessions, I recommend assigning one chapter for students to read for each of a week’s first two sessions and use the third session to discuss remaining issues that that are blocking student progress and doing activities that allow students to practice using the ideas.

Exercise Boxes

The boxes in the text are extremely important: they provide a detailed exposition of specific topics whose presentation in the chapter itself would derail the logical flow of the argument. The exercises in those boxes are essential in directing and guiding students as they work out some of the details for themselves, something that helps them “own” the theory in a way that is very difficult to achieve otherwise. Even failing (after a solid attempt) to do an exercise provides both the student and instructor with useful information about what specific issue(s) might be blocking that student’s progress. (I also strongly recommend that instructors do the exercises themselves when teaching the course the first time to help them appreciate the student experience.)

Encouraging Preparation

However, these boxes only serve their role if students internalize that reading a chapter carefully and working through all its exercises is essential if one is to be prepared for class. Careful reading of a textbook, much less doing exercises before class, are rarely part of any institution’s basic culture, so some way of rewarding this behavior is necessary. One method I have found useful is the following.

• Students are told to read the chapter and handwrite exercise solutions in each box. They are encouraged to make a serious effort on each exercise, but if they get stuck for more than 10 minutes, they should go on.
• Then they view solutions I have posted (see below) to correct their work using a green or purple pen. They then use their smartphones to scan the work and submit it electronically well before class (say, 6 am).
• Before class, I then look at each submission and grade it (0 = no effort, 1 = inadequate effort, 2 = adequate effort). My focus is on effort:  work on an exercise can be "adequate" and yet not correct or even complete if the student (a) clearly spent serious effort on each exercise and/or has described where and why they got stuck, and (b) has corrected their work adequately. This rarely takes more than a few minutes per student.

A student's total pre-class score might comprise 10% to 15% of their grade, and I typically drop the two lowest scores to give students some flexibility (and to avoid listening to excuses). This method (a) provides and incentive for students to do the work, (b) signals that I consider it important, and (c) shows me where students are having trouble so that I can target class activities to address those difficulties. Correcting their own work also exposes students to expert-like problem solving. There is really no reason to cheat, as no part of the grade depends on anything but effort, and students at this level typically know that working on these exercises is essential to learning. However, this approach assumes a class size less than about 15 students (otherwise, the grading becomes tedious).

For some other possibilities, follow this link.

Class Activities

Another way to encourage student preparation is for the instructor to resist the strong temptation to lecture about the chapter and/or do exercises on the board. Doing either of these things clearly signals that the instructor is assuming students have not prepared, and so provides them with an excuse not to do all that preparation work.

Instead, I strongly recommend designing class activities that encourage students to talk to and learn from their neighbors and provide the opportunity for them to solidify their understanding by getting expert feedback on their work in class. Educational research has abundantly shown such active methods to be far more effective at helping students develop true and flexible competence than even the most brilliant lecture. This also sends the message that being prepared is essential.

Helping students understand this is also important. An analogy I often use is that learning to be a physicist is like learning to play the piano or a sport. A piano teacher or coach who merely demonstrates how to play brilliantly is doing a poor job: a good coach or piano teacher chooses things to practice beforehand, asks students to play, and then gives expert feedback on how to do better.

Some of the homework problems in the book can be directly used as such classroom activities. For example, almost any of the homework problems in chapter 1 would work well as class activities: they require careful thinking (and the opportunity for discussion and feedback) but not a lot of calculation. One might also have students work on a small piece of a more complicated problem. In a sufficiently small class, using Socratic methods (“What do we do next?”) to guide students through working an example collectively can also be a useful activity.

Sometimes, a short (less-than-15-minute) lecture on something that a number of students are finding difficult even after reading the chapter can be good, even necessary. Just resist the temptation to do this all the time. A student-based active classroom can feel chaotic, but behind the chaos, real learning is happening (trust me!).

Homework Problems

I typically assign three homework problems per chapter for students to submit each week. In an upper-level course like this one, I generally have students scan and electronically submit “initial efforts” by a deadline and then use solutions posted online (after that deadline) to correct their own work using a green or purple pen and submit the result on paper. I grade each corrected solution on a 10-point scale (up to 4 points for a good initial effort, up to 3 points for a valid and complete correction, and up to 3 points depending on how much correction was necessary). This process exposes students to expert solutions, encourages them to be self-critical about their own work, and saves me a lot of grading time. Again, I automatically drop the five lowest scores to give students some grace.

For more details, see this sample syllabus (PDF).

Signing Up to Post Solutions Online

The schemes described above require an instructor to post selected solutions online. But please do not to simply scan and post solutions publicly online for everyone to see (that would also violate the publisher’s copyright). Instead, this website provides a way for certified instructors to post problem solutions securely, behind an instructor-chosen password, and for an instructor-designated time window. To apply for certified instructor status, see the Resources section below.