Tips for Teaching Virtually with Smartphone Sensors

I have been recently following a lot of online conversations about teachers who are being asked to teach in some of the toughest circumstances. In response, I'd like to offer some tips for those who might decide to try to use smartphone sensors—perhaps for the first time—to give their students some hands-on experiences.

However, I do want to make it clear that although I taught high school physics and engineering for seven years in the great state of Illinois, I haven't been in the classroom for almost six years. Even during that short time, despite my best efforts, I likely sometimes used flawed pedagogy, wasn't as responsive to the needs of my students as I could have been, and wonder if I sometimes used technology for the right reasons in the right circumstances. Take my reflections as you like, add to them, and provide constructive criticism. I'll update accordingly! (You can reach out to me at support@vieyrasoftware.net).

Below are six tips that come to mind with respect to teaching with smartphone sensors based on my own experiences in the classroom and with at-home projects, as well as based on what I've gleaned over the years of seeing teachers try to use them.

1. Consider Goals for Educational Technology and Technology Education

Why use smartphone sensors? Many teachers are attracted to using smartphone sensors because they are accessible for many students and can quantify scientific observations that can lead to deeper understandings about physical principles. They can be used as real-world problem-solving tools that have applicability beyond "science class." They can be cheap or no-cost replacements for expensive or hard-to-acquire commercial probe ware.

However, be wary of using technology for technology's sake, and falling into the trap of spending more time on the learning curve of technology use (a part of technology education) than actually reaping the benefits of using educational technology to advance science goals. Dropping a ball down a flight of stairs at home to manually calculate acceleration due to gravity might be simpler (and safer) than dropping a smartphone to produce an acceleration-time graph. If the goal is to just achieve a good value for acceleration due to gravity, there might be no need for technology. However, if the goal is to improve graph reading skills, it might make sense to use it. Don't overlook the simpler, less "tech-y" solutions without considering your educational goals.

2. Consider Accessibility

Not all students have smartphones, and not all students will have smartphones with all of the possible sensors or visualization capabilities. However, I don't generally view that as a good reason to reject using them outright when there are otherwise good pedagogical reasons for doing so. Rather, I like to think about differentiation and collaboration. Might students be embarrassed about not having a smartphone to collect data? Privately survey students about their willingness to use their phone for data collection, and form collaborative groups in such a way as to ensure that there are at least one or two people who can collect the data and share it with their peers.

Might smartphones not be an option for some groups? Offer differentiated tasks from which students can choose, such as allowing one group to have a team member that measures acceleration of their phone as it slides down a ramp, while another group collects data from The Ramp simulation from PhET. Allow groups to decide to collect sound intensity data from a tone generated by a speaker, or collect similar data from the Waves Intro simulation from PhET. Students can effectively crowdsource the principles behind the data they collected, and compare real-world data to simulated data. The engagement experience might be different for students, but it might match their preferences, interests, and available technology.

3. Explore Relationships with Qualitative --> Manual Quantitative --> Exported Quantitative Data

If you decide to introduce students to smartphone sensor data, do so gently. Although kinematics often comes first in traditional high school and college coursework, the algebraic relationships behind them are notoriously difficult to understand. The fact that the smartphone relies upon an accelerometer makes it particularly tricky to use the smartphone for the first time at the start of most courses in a way that is really meaningful to students. (I don't expect most students to understand the concept of acceleration until they have a really solid grasp of constant velocity motion, and g-forces are conceptually problematic for students who don't have a good understanding of force diagrams and Newton's laws).

I generally recommend that students first observe data qualitatively, such as looking at graphs (or even digital readouts) of "single-dimension" data such as barometric pressure, light intensity, or sound intensity. While it might appear a bit elementary, I really do think that tools like the Play mode (accessible only on Android) do a good job of introducing users to sensors in general and different kinds of readouts.

Next, I find it helpful to direct students' attention toward manually collecting quantitative data, again either from digital readouts of graphs. For example, a good introductory lab might be to have students determine the relationship between height off of the ground (measured with a meter stick, tape measure, or arbitrary units such as hand-lengths) and barometric pressure. Students can even produce graphs of pressure versus time, and convert them into graphs of position versus time (and velocity versus time).

Exported quantitative data sets should probably come last. Most of the major functions on Physics Toolbox have a "plus" symbol, which allows data to be recorded and then exported in a .csv format. These data can be uploaded into a graphical analysis tool such as Excel, Google Sheets, or LoggerPro, for plotting and manipulation. However, this takes quite a few different steps with which novice students might struggle. Teachers sometimes do demonstration labs and showcase how to export and then import and analyze data. Students can follow these instructions asynchronously as they work on their own computer screens.

Keep in mind that the inconsistency and sloppiness in data collection that teachers sometimes see in the classroom is likely to persist even under virtual teaching, although teachers are unlikely to get a window into what students are actually doing. Allow students time to collect data, initially use reliable phenomena (such as light/sound intensity, as opposed to human-generated phenomena, such as an attempt at creating uniform accelerated motion by spinning in a circle), and consider having students document their data collection processes to verify their work, such as having a parent record their child's hands as they collect data.

4. Use Data to Solve Ambiguous or Open-Ended Problems

Although as a former Modeling Instruction teacher I have something of a love affair with deriving natural principles from raw data, don't forget about the opportunity to revolutionize the traditional problem-solving scenarios. A single, validated data point from a sensor can serve as an opportunity for students to turn problem-solving on its head: "Here's a measurement, what question is it answering, or what question can I ask?"

For example, consider the student who has a panpipe at home. They might take a picture of the panpipe and register the tone produced by resonance as the student blows across the top. The student might be able to generate a variety of questions, such as, "What must be the length of the panpipe?" "How would the panpipe sound different if I cut off the bottom of the tube?" Students can create scenarios and illustrate how they would solve the problem in a digital presentation or video, showcasing drawings of standing waves, assumptions about the speed of sound, calculations, and verifying measurements. Or, perhaps better yet, students can present a scenario to their peers and ask them to solve them, providing guidance and ultimately a solution against which to check.

As another example, students might want to estimate the height of the ceiling in their house, checking both the difference in barometric pressure and using trigonometry with the inclinometer. Students might investigate the waveform of the voices of family members singing the same note, estimate the speed of a passing ambulance using the spectrum analyzing, or identify the relationship between note frequencies on their musical instruments.

In some cases, students' answers must be evaluated based on reasonableness and relative accuracy. These kinds of problem-solving scenarios, based on real (but sometimes not teacher-verifiable) data, lead to very different results from students. However, I always believe in quality over quantity. Especially in a digital era, my gut feeling is that we need to emphasize student creativity over classroom coherence.

5. Consider Liability Concerns

I've been hearing some worrying stories about teachers being told that students may not do any kind of "at home labs" for fear of liability in case a student (or their technology) should get hurt. Up to a point, these are legitimate concerns (as someone who sometimes sent my students home with family-based homework, I'm not sure I can distinguish between a lab activity and homework). I do strongly suggest that teachers consult with their schools about how to minimize liability, such as including special clauses in lab safety contracts that are signed by parents that ensure that personal technology use is voluntary and that parents should be present when students are doing lab activities. I generally am a believer in "reasonable risk," but it is important to ensure that the threshold for reasonableness is clearly defined and understood by students, parents, and administration.

6. Consider the Impacts

Lastly, consider the impacts of technology-based activities on your original educational goals for your students. Did the activities increase or decrease equity gaps? Consider looking at technology accessibility as well as engagement and achievement of students. Then, maintain or modify your teaching. As is true with every academic year, this one is going to require lots of self-reflection and flexibility!