Alternative Assessment in NATS1516: Water Pollution

In this two-part blog, Dr. Domenikos discusses an authentic assessment strategy to help students experience what it feels like to be a scientist, in the context of a large first-year natural science course. Part 1 of this blog is available here.

As an instructor of Natural Science courses (general education science courses for non-science majors), I am constantly looking for ways for my students to see the applicability of the lecture material and understand its real-world context. NATS1516: Water Pollution (current enrolment is 175 students) is a brand new first-year general science course focused on studying the environmental and health impacts of water pollutants. I often receive feedback from students that by taking my NATS courses they enjoy “feeling like scientists”. Therefore, I wanted to design an assessment to really give them an experience of being a scientist.

In NATS1516, I designed an alternative assessment where students use Water Quality Test Strips to test the water quality of a variety of water samples. Students write their own scientific question and hypothesis, plan out their methodology, conduct their experiment on their own at home, and write a scientific report to highlight their findings.

Some example scientific questions that students have designed are:

Is there a different in quality between filtered tap water, snowmelt, and the Strong Pond water at York University?

Is there is a difference in quality of bottled water sold in various countries worldwide (e.g. Sole from Italy vs Dasani from Canada)?

The Water Test Strips

The water test strips used for this assessment are: SJ Wave 16-in-1 Drinking Water Test Kit purchased from Amazon. The strips test for 16 different water quality parameters (total hardness, free chlorine, iron copper, lead, nitrate, nitrite, MPS, total chlorine, fluoride, cyanuric acid, chlorine dioxide, QUAT/QAC, total alkalinity, carbonate and pH). The test kits cost roughly $35 for 100 strips, and I am currently paying them using my PER (but am hoping to get funding to cover them through the AEF in future years). The strips are incredibly easy and straightforward to use; users simply submerge the test strip into the water sample for 2-5 seconds, hold the strip horizontally for 30 seconds, and compare to a colour chart provided indicating the concentration/level for each of the parameters.

Student Use of the Water Test Strips

Currently, there are 175 students in NATS1516 and they were instructed to design an experiment that required a minimum of 2 and a maximum of 4 test strips. I bring the test strips to class and the students sign out the total number of strips they require for their experiments. Students collect their water samples at their convenience, sign out the test strips from class, and then conduct their experiment at home. Once the experiment is performed, students immediately record their data and then are ready to analyze the data to present in their final scientific report.

What I hope the students get from having this experience?

By completing this alternative assessment, I hope students gain an understanding and appreciation for the scientific process (the process of asking a question and designing an experiment to answer that question) and see the applicability of the theory taught in lecture applied in a real experiment. In addition, my goal is for students to gain a better understanding of the importance of their study of water pollution globally. In doing this assessment, students strengthen their problem-solving skills, their critical thinking, and analytical skills, and have a greater confidence in their ability to understand and apply the course material in a real-world context.

Things you learned/would do differently next time?

Now that I see the success of having students design and conduct their own water quality experiment, in the future I would apply for AEF funding to purchase higher quality water test strips. While these strips are useful, others are available that test a wider variety of parameters, such as the presence of bacteria and other pathogens, that would broaden the scope of questions students could ask and therefore further enhance their connection with the experience.

For other educators interested in using these water quality test strips for use in their classes, I have found them incredibly user friendly and very easily to extract data for analysis. Their accuracy is not 100% (which is why their purchase price is fairly low) but it still allows students to compare samples relative to one another. These strips (or similar ones) would be ideal for any course which has content on water quality (or specifically drinking water quality). If strips cannot be purchased, I have found a number of virtual labs on YouTube where educators have recorded themselves testing a variety of water samples for parameters such as bacterial presence or biological oxygen demand, and therefore those videos can be accessed and watched by the students for free.

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