Infusing the Science Lab with Guided Inquiry

by John R. Walkup, Ph.D.

Every year, I find about 40% of my students as solid, even exemplary learners and another 40% as struggling or even failing learners. Some, but not all, of the problems can be laid at the feet of the students, many of whom put forth less than a solid effort to meet the course challenge. This problem has long dogged education institutions and Fresno State is no exception. But we cannot ignore other causes for low student performance. In physics, many problems center on weaknesses in the physics lab.

The lab activities I have been teaching at Fresno State are so old that I remember using them as a teaching assistant 30 years ago. Back then, the idea was that if we could get students to engage in activities that obey the laws of physics and ask them to review their experimental results, this would reinforce their understanding of physics.

Therefore, our lab activities centered on students following clear directions, including how to set up the apparatus, what to measure, how to measure it, and how to record results. Once finished, students were provided "canned" formulas derived from fundamental principles; students then substituted their numerical results for measurement and verify that the formulas offer good results. As students make mistakes, the activities are redesigned to stamp out such problems.

For example, students often forget to convert units. leading to wild calculations where the gravitational acceleration constant of the Earth is found to be (say) 92 m/s², rather than the more sane 9.8 m/s².

Such mistakes tend to drag out the lab activities, so to make the lab more efficient we often create a series of steps to ensure that students make the proper conversion of units, rather than letting students make the mistakes on their own. As a result, students are more likely to get reasonable results in less time. They just don't learn much.

I call this form of lab activity paint by numbers. Metaphorically speaking, students are given a canvas where the different colored parts of the painting are marked by perimeters, then color in each area according to the rules (e.g., 1 = red). But painting by numbers doesn't really teach art because

• Students are not free to express themselves creatively (the essence of art)
• Students do not need to apply any knowledge of art while painting.

This is not to say that the results of paint-by-number exercises don't look like art. I once painted the Cutty Sark when  I was eight years old using a paint-by-numbers kit and it looked like a real ship. In this sense, paint-by-numbers exhibits the features of Feynman called a "cargo cult," where the design of activities focuses on superficial resemblances. In the language of Webb's Depth of Knowledge, our existing lab exercises comprised a long string of DOK-1 activities, followed by a few DOK-2 questions. As such, our existing labs rarely transcended DOK-2. (We will fix that.)

Riding along with low academic performance was low student engagement. Because our existing lab activities require little in the area of cognition, students disengage easily. As one student said this fall, "I can sleepwalk through it [the lab activity]." Whenever a problem surfaces, students simply raise their hand and the teaching assistant gladly answers their question.

For example, I was observing one lab experiment where students were told to find the mass of a cart riding along an air track. They wondered if they should also include the mass of the flag used on top of the cart for tripping the photogate sensor. The teaching assistant responded "yes" and then went on to explain that the mass of the flag must be included because the forces acting on the cart must accelerate the flag too. The students heard his explanation, but they didn't really listen to it. They had a question and they got their answer. Stepwise lab activities tend to produce such low-level engagement because students are more interested in getting correct results than learning the scientific process.

In the summer of 2017, I decided to revamp the existing physics labs using a teaching method called inquiry. There are three major types of inquiry-based lessons.

1. Open inquiry -- students lead the scientific question, design, scientific investigations or experiment, and communicate the results.
2. Guided inquiry -- the teacher selects the overarching question to investigate and then students engage in methods to scientifically determine the answer;
3. Structured inquiry -- students follow teacher-led directions toward an outcome that they must assembled from what they experienced.

Only the last two types guarantee a reasonable coverage of the course content. At best, our existing lab activities aligned to the third type of inquiry, that is, structured inquiry. Even those were rare.

Another reason for melding the old labs into inquiry-based instruction was to align our physics instruction to the Next Generation Science Standards (NGSS). While many relegate the NGSS to purely K-12 concerns, the NGSS holds great promise for college education as well. Learning is learning, after all.

With guided inquiry, our students will take much more ownership of the learning process, planning their own approaches to meeting challenges and, when appropriate, their own experiments. They will assume the responsibility for raising questions and answering them on their own. In my next installment, I will describe guided inquiry deeper and connect it to a curricular model called Cognitive Rigor.