September 2022 | Nuts & Bolts
Teaching with Project-Based Learning in the High School Chemistry Classroom
By Barbara Nelson
Why use Project-Based Learning?
When children are very young, they have an unquenchable thirst for knowledge. They spend their entire day trying to walk, talk, and be like their parents. But in my experience, by the time they reach high school, many have lost interest in learning, and desire only to earn good grades.
How can a teacher rekindle that desire to learn? How can we teach students to learn simply because they want to gain knowledge? As described in a post on Edutopia, one way to help students overcome apathy is to build bridges between a student’s interests and the content you wish to teach.
My solution to building such bridges has been Project-Based Learning (PBL). According to the home page of PBL Works, “Project Based Learning is a teaching method in which students learn by actively engaging in real-world and personally meaningful projects.”
PBL is different from simply doing a fun project at the end of a unit, or on the day before break. PBL uses authentic projects that require students to use the information that we want them to learn. Ideally, this means that they involve student choice and an actual, real-world audience. Projects are not just assignments that are turned in and thrown away as soon as they are graded.
Traditional projects versus PBL
A big difference between PBL and the types of projects that I assigned earlier in my career is how students view the projects.
Early in my career, I taught each unit in a traditional manner, then had students complete a related project at the end of the unit. I have heard this type of learning activity called a “dessert project,” because it is a fun application of the material students have just learned. For example, I used to do an end-of-unit project that required students to complete a qualitative analysis lab as their semester final exam.
In contrast, a PBL approach introduces students to a problem-based project at the beginning of the unit, and students then learn the material as they work on the project. In the process, we show them they actually need to learn the material in order to complete the project. For example, in one PBL project I’ve used, students were introduced to the water quality issues that recently occurred in Flint, Michigan. Then they worked through analyzing a water sample, and finally created a news article or newscast about what occurred, and how the problem was analyzed.
Another difference between a PBL project and a traditional project is authenticity. A PBL project should be centered around a problem that allows students to easily see how a similar problem might occur in their life, such as water quality testing. In that particular example, the way I used to present the project lacked this component, and instead was simply a high-stakes, stressful lab experience. Students turned in their data and identification of an unknown; but after grading the paper, I tossed it — effectively throwing away days of their work. Looking back, it seems clear that this would not encourage students to work for anything except a grade. However, when students create a product that is real to them, and they know will be viewed by others, I’ve seen that they become motivated to create something in which they can take pride.
My journey to PBL
After the Next Generation Science Standards (NGSS) were developed in 2013, many states, including Idaho where I live, began to adopt similar standards. The NGSS standards are written to emphasize teaching students to use information rather than merely memorize facts. For my recertification credits, I began taking classes offered by our state on the new standards, which led me to PBL. PBL not only seemed to emphasize using information, but also designing and refining experiments.
Initially, I could see the value of teaching students using PBL, but I struggled with how to implement it. I loved what I was learning and wanted that sort of experience for my students, but authentic projects in high school chemistry were hard to find.
While I was attempting to incorporate PBL into my teaching, I also decided to change schools, and began teaching in a large school whose entire science department was focused on PBL and mastery learning. All of our science teachers are working to implement PBL, but I am the only chemistry teacher among them, so I am able to experiment in my teaching strategies.
My new chemistry teaching job happened to come with an astronomy class assignment. Since I had never taught astronomy before, I started tackling this task by looking up the standards. There weren’t many, so I decided to include Engineering and Design standards as well. I took advantage of having few required standards, and used the time savings to implement projects to support a PBL approach.
From the beginning, teaching this class was amazing. Students came in each day excited to work on their projects, voluntarily worked on them at home, and wanted to take them home afterward to show their parents. With this success, I became determined to implement PBL in my chemistry classes as well.
From then on, every spare minute was spent scouring the internet, looking for authentic project ideas. In the past, I had found it easy to find traditional project ideas. But often they were either not authentic, or did not require students to learn the content that was necessary in a high school chemistry class. I developed PBL units that taught standards and featured moderately authentic projects, and began to implement them.
I am continuing to work on improving the authenticity of the projects. Not all projects are as relevant as I might like, and I would like to have more students present their projects to an audience of experts (such as members of the community related to the project topic). Another struggle that I have encountered is finding projects that can be introduced at the beginning of the unit. Sometimes I’m in a non-ideal situation, when I have information that has to be presented to students before I can introduce the project.
Some examples of PBL Units
(Including NGSS Performance Expectations that relate to the content in each unit)
- Something Funny in Flint, Michigan (HS-PS1-5, HS-PS1-6)
This unit is introduced with a video clip of a news story on the problem of lead in the drinking water in Flint. I collect water from a local river and contaminate the sample in order to represent a variety of water samples (for example, using acids, aluminum, but not lead due to its hazardous properties). Students analyze the water to determine what it is contaminated with. This activity involves solubility, equilibrium, and pH standards. We do conventional and conductimetric titrations to determine the amount of acid in the water. We also check for nitrates, phosphates, and coliform bacteria. As a final task, students create a newspaper article or newscast to explain what they found in terms of water quality.
- Tanker Car Implosion (HS-PS3-2)
This unit covers the gas laws, and is introduced with a MythBusters video in which a tanker car is imploded by filling it with steam, capping it, and spraying it with cold water. Students conduct a series of inquiry labs to understand the gas laws. As a culminating activity, students create particle diagrams showing what is happening inside the tanker car before capping, as the car is cooling down, and after the implosion.
- Is Biodiesel a Solution to the World’s Energy Problems? (HS-PS3-1, HS-PS3-3)
To engage students in this unit, I start by sharing energy statistics. I also invite a guest speaker from a car dealership that sells vehicles that run on biodiesel (a video clip could work here as well). Students research a recipe for the synthesis of biodiesel and synthesize it. Then they compare it to conventional diesel in terms of soot and carbon dioxide production, energy per mole, and gelling in cold temperatures. Students design their own experiments to test these parameters. As a culminating activity, students create a trifold brochure answering the question based on their data. This meets standards of energy calculations and designing an experiment to analyze changes in energy.
- Alcohol Detective (HS-PS1-3)
This unit focuses on the concepts of intermolecular forces and polarity, as well as the processes of distillation and gas chromatography. Students are engaged in a scenario involving the seizure of bootleg alcohol. There are two suspects, both of whom have stills — and, using gas chromatography, students attempt to identify which still produced the seized alcohol, based on contaminants found in the sample. Note: It has required several grants to purchase gas chromatographs and organic kits for use in this unit.
Where we are now
Students love the PBL units! As our science department has been implementing PBL, we have seen large enrollment growth in our advanced science classes, and increases in average AP test scores. In addition to content knowledge, students are learning to use technology, present data, and work with other students. These are skills that my students were not previously learning through traditional teaching. What’s more, the problem-solving skills they are learning will continue to benefit them, whether or not they end up pursuing chemistry.
I still don’t feel like I am “there” yet. Some units could have better introductions or a more authentic final project. Sometimes the projects don’t flow as well as I would like them to, and I am trying to provide more choices to students. Though I know this will take time, I’m trying to add and improve each year, by picking the unit that I feel is the weakest and redesigning or fine-tuning it. I am also developing a network of community scientists who can be speakers and audiences, and also in helping to improve the projects.
Even with these difficulties, I feel that PBL is the solution to many problems that teachers face. Here are some of the benefits of PBL that I’ve experienced:
- Students come to class excited to learn every day. I never hear, “Why do we have to learn this?” I have a goal that if someone were to walk in my room and ask a student why they were doing a particular activity, the students could answer with a reasonable explanation.
- Class time is less stressful with PBL. The work of teaching PBL is in the development of the projects. Once the project begins, I am just a resource for the students, and each day is a joy. I have time to interact with students, and can help them learn at their own pace rather than forcing everyone to learn exactly the same material in the same way.
- Classroom management is easier than I experienced previously. Because the students are engaged, they want to learn and do their projects. As a result, nearly every student completes their project.
- Projects can allow for student choice in the nature of the activity, which increases engagement. Some examples of choices are creating an opening argument in a court case (for either the defense or prosecution), creating a news article or newscast, or choosing a variable to manipulate and test. When a project allows students to choose how they will demonstrate learning, and also has a less intimidating assessment piece, they are more willing to put in the effort to show me what they have learned.
- When students know that their project will be displayed or in some way presented to others, they are more concerned with creating a quality project.
- Projects are easily differentiated for students with special needs. I can modify the extent of the project or aspects of the quality that I require for submission.
- While students are working on projects, I am available to talk to them. I can give feedback on their work while getting to know them as a person so that they understand that they are more than “just a number.” Through their choice of a final project, I also get to know what they enjoy doing and where their interests and talents lie. I am also able to conference with students to help them set goals for getting caught up and planning for their future.
- Cheating is eliminated. The projects have enough variation that it is not possible to look up the answer on the internet. For example, the biodiesel brochures contain pictures of the analysis procedures, which are different for each group. The water quality project has students creating videos or news articles that are unique to each student. When we do science fair projects, I do not even need to have student names on the projects, because I have watched their progress and can identify each project by sight.
Once the projects are finished, I grade the final project using a rubric for what our state calls the Competencies. These represent a set of knowledge, skill and attributes that prepare graduates for life after high school. This allows me to grade students on their readiness.
It’s worth noting that my biggest barrier wasn’t my willingness to learn PBL, but rather, developing the project ideas. I spend a lot of time looking for ideas that I can modify to meet my needs and those of my students. The American Association of Chemistry Teachers (AACT) has been a helpful resource in my planning, as well as TeachEngineering. During my searches, I also look for dessert projects that I can modify to be the basis for a unit. Many times, I’ll find a project idea that is appealing, but just needs a little adjustment in order to work as a PBL. Examples include removing step-by-step guidance for students, and instead tasking students with designing their own procedures, or changing the final product to increase its relevance or authenticity. I’ve found this to be a manageable way to make successful progress on my PBL journey.
I constantly keep my eyes open for ideas, events, and occurrences that can be the premise of a new PBL opportunity. I discuss ideas with colleagues, approach business leaders for topic input, and try to take every class about PBL that crosses my path. I’ve found that this process has been both addictive and rewarding for myself and my students! I’m eager to continue to move forward and learn more. I encourage you to get involved as well, and bring the excitement of PBL to your own classroom!
(article cover) Bigstockphoto.com/mkabakov