In my mind it is hard to get students to do pre-class homework (“pre-reading”) with much more than an 80% completion rate when averaged out over the term. It usually starts higher than this, but there is a slow trend toward less completion as the term wears on. After taking a more careful look at the five introductory courses in which I used pre-class assignment I have discovered that I was able to do much better than 80% in some of the later courses and want to share my data.
Descriptions of the five courses
The table below summarizes some of the key differences between each of the five introductory physics courses in which I used pre-class assignments. It may also be important to note that the majority of the students in Jan 2010 were the same students from Sep 2009, but not much more than half of the Jan 2013 students took my Sep 2012 course. For Jan 2013 only two of the students had previously taken a course with me.
|Course||Textbook||Contribution to overall course grade||Median completion rate (the numbers in brackets show the 1st and 3rd quartiles)|
|Sep 2009 (Mechanics)||Young & Freedman – University Physics 11e||Worth 8%, but drop 3 worst assignments. No opportunities for late submission or earning back lost marks.||0.73 (0.62,0.79)|
|Jan 2010 (E&M)||Young & Freedman – University Physics 11e||Worth 10%, but drop 2 worst assignments. No opportunities for late submission or earning back lost marks.||0.78 (0.74,0.89)|
|Sep 2011 (Mechanics)||smartPhysics||Worth 8%. Did not drop any assignments, but they could (re)submit at any point up until the final exam and earn half marks.||0.98 (0.96,0.98)|
|Jan 2012 (E&M)||smartPhysics||Worth 8%. Did not drop any assignments, but they could (re)submit at any point up until the final exam and earn half marks.||0.94 (0.93,0.98)|
|Jan 2013 (E&M)||Halliday, Resnick & Walker – Fundamentals of Physics 9e & smartPhysics multimedia presentations||Worth 10%. Did not drop any assignments, but they could (re)submit at any point up until the final exam and earn half marks.||0.93 (0.87,0.97)|
Overall the style of question used was the same for each course, with the most common type of question being a fairly straight-forward clicker question (I discuss the resources and assignments a bit more in the next paragraph). I have not crunched the numbers, but scanning through results from the Jan 2013 course shows that students are answering the questions correctly somewhere in the 65-90% range and the questions used in that course were a mishmash of the Jan 2010 and Jan 2012 courses. Every question would have an “explain your answer” part. These assignments were graded on completion only, but their explanation had to show a reasonable level of effort to earn these completion marks. Depending on class size, I did not always read their explanations in detail, but always scanned every answer. For the first couple of assignments I always made sure to send some feedback to each student which would include an explanation of the correct answer if they answered incorrectly. Each question would also be discussed in class.
A rundown of how the resources and assignments varied by class:
- For Sept 2009 and Jan 2010 I used a Blackboard assignment to give them the three questions each week and told them which sections of the textbook to read, and I didn’t do much to tell them to skip passages or examples that weren’t directly relevant.
- For Sept 2010 and Jan 2012 I used smartPhysics (link to UIUC PER group page, where they were developed). These consist of multimedia presentations for each chapter/major topic, which have embedded conceptual questions (no student explanations required for these). After they are done the multimedia presentation, they then answer the actual pre-class questions, which are different from those embedded in the multimedia presentation. For the most part, the questions in their pre-class assignments were similar to the ones I was previously using except for the smartPhysics ones were often more difficult. Additionally, my one major criticism of smartPhysics is that I don’t feel they are pitched at the appropriate level for a student encountering the material for the first time. For more on this, have a look at the second bullet in the “Random Notes” section of this post I did on pre-class assignments (link). One of the very nice things about smartphysics is that everything (the regular homework, the pre-class assignments and the multimedia presentations) all used the same web system.
- For January 2013, I was back on assigning the pre-class assignments through Blackboard. The preamble for each of the pre-class assignments pointed them toward a smartPhysics multimedia presentation and the relevant sections of the textbook we were using. Students could use one, the other or both of these resources as they felt fit. I don’t think I ever surveyed them on their use of one over the other, but anecdotally I had the sense that way more were using the multimedia presentations.
I present two graphs showing the same data from different perspectives. Figure 1 shows how the fraction of the class completing a given pre-class assignment varies over the course of the term. There is a noticeable downward trend in each course. Figure 2 shows the fraction of assignments completed by each student in each class.
There is clearly a large difference between the first two courses and the final three in terms of the rates at which students were completing these pre-class assignments. The fact that I saw 98% of these assignments completed one term is still shocking to me. I’m not sure how much each of the following factors contributed to the changes, but here are some of the potential factors…
- Multimedia presentations – students seem to find these easier to consume than reading the textbook. There is a study [Phys. Rev. ST Physics Ed. Research 8, 010103 (2012)] from
Homeyra Sadaghiani at California State Polytechnic University where she did a controlled study comparing the multimedia presentations to readings in textbooks, and used the same pre-class assignments for both. In addition to finding that the multimedia presentation group did slightly better on the exams, she also found that the students had a favorable attitude toward the usefulness of the multimedia presentations, but that the textbook group had an unfavorable attitude toward the textbook reading assignments. But she also mentions that the multimedia group had a more favorable attitude toward clicker questions than the textbook section, and this alone could explain the difference in test performance as opposed to it having to do with the learning which takes place as part of the pre-class assignments. If the students in one section are buying into how the course is being run more than another, they are going to do a better job of engaging with all of the learning opportunities and as a result should be learning more. There are a variety of reasons why reading the textbook may be preferred to have them watching a video or multimedia presentation, but you can’t argue with the participation results.
- Generating buy-in – I have certainly found that, as time wears on, I have gotten better at generating buy-in for the way that my courses are run. I have gotten better at following up on the pre-class assignments in class and weaving the trends from their submissions into the class. However, for the Sep 2009 and Jan 2010 courses, that was the most personal feedback I have ever sent to students in an intro course on their pre-class assignments so I might have expected that getting better at generating buy-in might cancel out the decreased personal feedback.
- Changes in grading system – This may be a very large one and is tied to generating buy-in. For the first two courses I allowed them to drop their worst 3 or 2 pre-class assignments from their overall grade. In the later courses, I changed the system to being one where they could even submit the assignments late for half credit, but were not allowed to drop any. In the latter method I am clearly communicating to the students I think it is worth their time to complete all of the assignments.
In poking around through the UIUC papers and those from Sadaghiani, that 98% completion rate from my Sept 2011 course is really high, but is going to be an overestimate of how many people actually engaged with the pre-class material as opposed to trying to bluff their way through it. The smartPhysics system also gave them credit for completing the questions embedded in the multimedia presentations and I’m not presenting those numbers here, but when I scan the gradebooks, those that received credit for doing their pre-class assignments also always received credit for completing the embedded questions in the multimedia presentations. But, it is possible to skip slides to get to those so that doesn’t mean they actually fully consumed those presentations. Based on reviewing their explanations each week (with different degrees of thoroughness) and then docking grades accordingly, I would estimate that maybe 1 or 2 students managed to bluff their way through each week without actually consuming the presentation. That translates to 2-3% of these pre-class assignments.
Sadaghiani reported “78% of the MLM students completed 75% or more of the MLMs”, where MLM is what I have been calling the multimedia presentations. Colleagues of mine at UBC found (link to poster) that students self-reported to read their textbooks regularly in a course that used a quiz-based pre-class assignment (meaning that students were given marks for being correct as opposed to just participating, and in this case were not asked to explain their reasoning). 97% of the students actually took the weekly quizzes, but there is a discrepancy in numbers between those that took the quizzes and those that actually did the preparation.
With everything I have discussed here in mind, it seems that 80% or better is a good rule of thumb number for buy-in for pre-class activities, and that one can do even better than that with some additional effort.