Johnson - Revamping 117M

The Setup

117M is mechanics for pre-meds. The course is considered calculus based but this really just amounts to taking derivatives to do error propagation.
The existing structure is one lab a week for a total of 11 labs. Lab is scheduled for 3 hours but the experiment rarely takes longer than 2 hours and students complete a free form lab report at home.
The course is taught by 8-9 TAs in the fall, 6 TAs in the spring and has an accompanying lecture that is a separate course. Jeremy is the head TA and Greg Sitz is the lab supervisor.

The Problems

Lab reports are long (probably take students 2 - 3 hours to complete at home) and take TAs a long time to grade. 1 credit hour is not worth the work needed for students to produce good lab reports.
Regardless of the quality of the lab report students remember next to nothing from the experiment or the lab report the following week. There is a real “just grind it out” attitude towards the work in this course.

The Fix?

A drastically new approach was tried on the last lab of the Fall 2009 semester (a pendulum lab).
For this week all “regular lab classes” were cancelled and instead TAs signed up to be available in the lab room for 12 - 15 hours during this week. This was a fair trade for TAs because for this lab the lab report was thrown out so TAs traded grading hours for teaching hours.
In this structure students can come in any time during the week to work on the experiment and can spend as much time as they need (including coming multiple days) on the experiment.
With the time constraint removed TAs were able to strip away the step-by-step instructions typical of the labs and instead give students a series of guided questions to answer.
- “Prove the period is independent of the mass. Step 1: hang the 50 gram mass...” was changed to “Investigate the relationship between the period and the mass. Take measurements using a variety of masses and use a graph of period vs. mass to express your results...”
By explicitly asking the questions you want the students to be asking themselves, you try to get them to think more like scientists.
Students still read a “background/theory” section in the lab manual before the lab so it isn’t completely inquiry based but students don’t understand much from the theory so it’s still built around guided questions much like an inquiry investigation.

No Lab Report

In lieu of a formal lab report the manual tells students to make 4 graphs during the experiment.
Once the student feels ready she takes her 4 graphs up to the TA. If the graphs are wrong the TA sends her back to the experiment. If the graphs are correct the TA asks the student 6 oral questions (ideally 2 easy, 3 medium and 1 hard).
Because students are nervous about oral quizzes they take their time and assure they really understand the experiment before going up for the quiz.
On average students spend 3 hours doing the experiment, a few minutes on the quiz and then are done when they leave the lab.
The oral questions come from a list of questions the TAs decide on before hand. Currently the pendulum lab has a list of 75 questions (divided into easy, med, hard) so students do not all get the same questions.
TAs also agree before hand on what kind of answers can receive partial credit, how much partial credit and what, if any, additional information TAs are allowed to offer during the quizzes.
A student’s grade on the pendulum lab consists of 40 points from the graphs and up to 60 points from the oral quiz.

Does It Work?

Talking to students during the pendulum lab and during the final exam students seem to have understood more and retained more from that lab than from other labs.
Last semester 1 lab was done this way. This semester 2 of the labs are being done in this format. The main obstacle to doing all the labs this way is simply taking the time to rewrite the lab manual and write oral questions.
Student response seemed to be positive last semester. Some students were uncomfortable with an oral quiz but this is expected and can be overcome.
The number of TAs dictates what hours each day the lab room can be “open” to students (ideally two TAs present at all times). This semester with less TAs just means a slightly smaller window during which students can come in to do the lab.
There was a “Thursday night rush” as students put the lab off until the last minute. The more this style of lab becomes the norm for this class the less of a problem this is likely to be.
Because students come in whenever they want they may be working during a different TA’s shift than the TA they are used to. Students join up into groups based on when they come to lab. This involves mixing groups across classes but did not seem to pose a problem for getting students a group to work with.