Public Lab Research note

Tracking Plant Health Using Visible and Infrared Light -- Initial Experiences at an Arts High School

by Travis | June 10, 2015 16:57 10 Jun 16:57 | #11965 | #11965

Over the course of four weeks this spring, I utilized the Public Lab Infrared Curriculum Lessons in the two sections of my junior-level environmental science course at an arts high school in the southeastern United States.

My students are accepted to the school entirely on the basis of their artistic abilities and potential. As a result, my two sections are composed of students of all ability levels, including those who need remedial science, math, and/or humanities help, as well as those who perform far above grade level.

Each section was composed of approximately 30 students.

My initial impressions:

  • Lesson 1 seemed like it may have been a bit of a rehashing of material that the students had already seen many times before. Some students had previously reported “wetland fatigue” – that they’d heard about the plight of wetlands so many times in school, that they’d tired of thinking about it. I thought, therefore, that the most valuable part of the lesson would be the discussion of the impacts of the oil spill.

  • I expected Lesson 2 to go somewhat better, as it provides a great integration of material they’ve seen in several other classes, but had probably never seen in such a synthetic presentation.

  • Similar to Lesson 2, I expected Lesson 3 to be well-received by the students because of the novel way in which it integrates a set of topics that students had covered before but had not previously considered as an integrated whole.

  • Generally speaking, I thought that Lessons 2, 3, and 4 possessed the intellectual rigor that seemed appropriate to 11th grade. Lesson 1 contained aspects that might be a bit too elementary.

  • Overall, my major concerns revolved around aspects of timing and direction. I wanted to ensure that there was a balance between me providing verbal directions and the students self-guiding themselves through the activity. As provided in their original format on, the lesson plans don't clearly distinguish directions that are to be given by the instructor vs. read by the students. The original format of the lessons also doesn't make clear how (or if) students should explicitly respond to the questions posed. To help clarify the work for the students, I reconfigured each lesson into a traditional "lab activity" format, which I distributed to students before each class (see below for links).

  • Classes at my school meet for 90 minutes each day, so I gave students two consecutive days (three hours total) to complete each lesson.

For each lesson, students were assigned to work in a group of six. My post-class impressions of each lesson follow...

Lesson 1 (Wetlands, Water, and Oil):

  • As mentioned above, I formatted each lesson into a more traditional "lab manual" and distributed paper copies to each student. Here is the packet I made for Lesson 1: 1_WetlandsWaterand_Oil.docx

  • Students' self-reported impressions: They really enjoyed the group experiments and the oil spill demonstration with the paper towel. The most complaints were regarding group dynamics/student conduct (teenagers hate working in groups). Several students didn't like the reading (though a few did!) or the part where you put the bean in the bag, since they couldn't immediately see the point of doing this. A few students commented that the activity/packet was just too long (even though they were given two class periods of 90 minutes each to complete it!).





  • My impressions: Despite my initial concern about "wetland fatigue," this activity clearly added a new layer to student's understanding to the threats to wetlands. One of the greatest strengths of this lesson was that it contained something for all types of learners: a reading, hands-on activities, as well as a demonstration in which they got to sit back and watch.

  • By the end, my classroom looked like an oil spill. There was oil everywhere. But it was totally worth it.

Lesson 2 (More than Meets the Eye):

  • Here is the packet I made for Lesson 2: 2_More_Than_Meets_the_Eye.docx

  • In addition to the packet, I also copied and distributed the Worksheet and Shades of Grey illusion, provided by Public Lab: publab_worksheet_lesson_2.pdf and optical_illusions.pdf

  • This activity relies on color diagrams in the lab manual. Rather than printing color copies, I distributed normal black and white copies and provided students with a digital copy as well, which they viewed on their school-issued laptops.

  • Students' self-reported impressions: They enjoyed using the light box and filters and the Shades of Grey optical illusion activity. Topics that several people wanted to learn more about were: colorblindness, why we can only see the visible spectrum and how much is outside of it, and why do different people see different things (depending on age and other factors).


  • My impressions: This lesson really excelled in the way that it integrated material my students had learned as freshman (the physics of light) with material they had learned as sophomores (the biology of the eye) into an interesting concept (optical illusions) that could later be related to the topic at hand (monitoring plant health). For the colored objects, I used food (candy), which probably sweetened the deal for the students. Food is an instant winner with teenagers.

Lesson 3 (Photography in a New Light):

  • Here is the packet I made for Lesson 3: 3_Photography_in_a_new_light.docx

  • As in Lesson 2, the packet included many color images, so I distributed black and white copies and directed students to a digital copy to view the color images.

  • Students' self-reported impressions: Overall, students really enjoyed this lessons, especially when it came to taking pictures and taking the camera apart. Even though they enjoyed it, the predominant complaint was that taking apart the camera was hard and needed better instructions.

  • My impressions: Only one student was able to successfully disassemble the camera. Despite this lack of success, I think that leaving this option open to students is very important, as some students really enjoy this type of work. That being said, the resulting low number of IR-filter-removed cameras became the major stumbling block of the activity. I suggest having several pre-disassembled cameras available, but also leaving open the option that students could disassemble their own. There was widespread confusion among students when it came to using Infragram. The end result doesn’t give a legend bar in the new, so we went back to using the legacy version.

Lesson 4 (Environmental Monitoring):

  • Here is the packet I made for Lesson 4: 4_Environmental_Monitoring.docx

  • Students' self-reported impressions: They really liked taking pictures of the plants and watching their bean plants grow (even as Juniors in high school, they seem to most enjoy the most simplistic things). They were also very surprised that a camera could do so much with filters/NDVI. The students who are enrolled in the visual arts program were especially excited by this new discovery. Infragram was a major source of confusion and frustration.


  • My impressions: Timing of planting, stressing, and subsequent analysis of the bean plants is vital. The suggested timeline (stagger in one-week intervals) would have worked great. Due to the constant schedule juggling that is all too common in schools, I was not able to keep to this timeline. As a result, all bean plants (even the "unstressed" ones) were stressed by week four, so we substituted healthy vegetation from the school garden in place of the healthy bean plants. There was widespread confusion among students when it came to using Infragram. The end result didn’t give a legend bar in the new, so we went back to using the legacy version. Even then, I failed to see a photo that demonstrated the concepts that the example photos did (i.e., stressed/dying plants looking different than healthy ones). Despite using the correct filters and white balancing, I was never completely happy with the resulting colorized images that come out of Infragram. Even with these difficulties, I think students got a great take-home message: environmental monitoring (and scientific work generally) is difficult and problem solving is part of the discovery process. In lieu of the in-class presentations, I had the students write their own "research note." In my experience, asking students to do such presentations wherein each group is effectively giving a presentation on the same experiment is not effective. Since little new information is presented with each subsequent presentation, such presentations are not an efficient use of class time. Furthermore, students quickly bore of the repetition and become antsy.

Overarching concluding impressions:

  • If pressed for time, Lesson 1 is a great stand-alone lesson and could be used with great effect with no need to continue on to Lesson 2-4. Various parts of Lessons 2-4 could also be parsed out to make up a lesson on infrared monitoring.

  • These lessons were ideally suited to the ability levels of my 11th graders, though it could also work with freshmen if preceded by some introductory instruction on the physics of light.

  • I used a group size of 5-6 students. If resources allow, I suspect that groups of 3-4 students would have been much more effective at keeping all students engaged.

  • In my classroom of students with mixed abilities, the suggested two hour period per lesson seems to be appropriate for the average student. More advanced students were done in about 90 minutes; students who tend to take longer in my class required about three hours of diligent work to complete each lesson.

In summary, this is a great set of lessons. Even at the end of the school year, when students' attention span is at its lowest, my students really seemed to enjoy the activities, and also seemed to learn a lot. I'll definitely consider using them again next year.

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This is amazing feedback!!! Thank you so much, i can't believe i just saw this now.

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