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Adding Elements of Inquiry to Your Favorite Labs

Would you like to incorporate elements of inquiry into your lab work … without spending hours re-writing labs or breaking the bank buying new ones? Inquiry learning is one method instructors can use to encourage students to construct their own learning by considering questions about the subject matter.

When aspects of inquiry are present in a lab, it can help prevent students from simply going through the steps of a lab mechanically without thinking about what they are doing and why they are doing it. Inquiry lab experiences provide students with a wider context for understanding the material presented in the classroom, while improving student engagement and giving them a more authentic science experience.1 In addition, many teachers are required to include inquiry labs in their curricula; for example, the AP Curriculum Framework requires that at least six of the labs be “inquiry.” However, finding valuable inquiry labs can be difficult, costly, and time-consuming. In addition, many of the inquiry labs that one can find require more time than some teachers have available to them. For example, the official AP Chemistry lab manual, AP Chemistry Guided Inquiry Experiments: Applying the Science Practices, contains 16 inquiry labs, but some teachers find that they require too much time for use in their classrooms.

The idea of writing a complete guided-inquiry lab is quite daunting for most teachers, and open inquiry sounds too dangerous and unpredictable. Meanwhile, many teachers already have tried-and-true labs that work well for their students and within their time constraints. Elements of inquiry, hands-on exploration, and experimentation can be added to these confirmations or “cookbook” labs in order to increase student engagement, encourage students to discover questions and procedures, and to value scientific processes of data collection and communication.2

Discovery: Answering a question

Definitions of inquiry vary, but all involve the idea of students directly handling the science — whether it is coming up with their own questions and procedures, or applying observed phenomena to new situations. The goal is to encourage students to be actively engaged with the learning process, thinking about what they are doing and why. Structured inquiry involves students investigating a question using the materials and procedures provided. This can be made more student-centered by encouraging students to ask questions for themselves.

One of the simplest ways to do this is to show students a demonstration or video before a lab. A standard first-year chemistry lab involves flame tests. In order to increase student engagement, I created a new lab by merging an old confirmation flame test lab with the Mystical Fire lab created by educators Jesse Bernstein, Jeffrey Bracken, and Paul Price.3 Students watch a video of the product “Mystical Fire” and record their observations. (Alternatively, the instructor can create a mixture of salts and demonstrate a flame test with the mixture in lieu of the video.) Then the students come up with testable questions about the product and the flames they saw in the video.

Students require a lot of guidance in coming up with questions that are neither too broad (e.g., “What caused the red color?”) nor too narrow (“What color does magnesium sulfate produce?”). An example of a testable question is, “Do all sodium compounds produce the same color?” Once students have had their questions approved, they decide which chemicals to test, choosing from an instructor-provided list. Although they do not develop full procedures, they do decide which chemicals to test, and in which combinations. Students enjoy using their own powers of deduction to discover which salts might be in the “Mystical Fire,” and are surprised to find that some salts do not change the color of the flame much, if at all.

Through experimentation, students discover for themselves that the “first element” in the ionic compounds (i.e., the cation — although that term is unfamiliar to them at this point in the year) creates the different colors of flame. They also use a chart of colors and wavelengths to analyze the energies of the photons being emitted, relating the lab back to the concept of electron energy levels being different in different elements. Discovery involves students observing, classifying, and measuring. From their observations, they can then draw inferences about the world around them.

Discovery: Designing a procedure

Another typical modification of a confirmation lab is “guided inquiry”: having students create a procedure to investigate a given question. This often feels scary to teachers. How can students be trusted to create their own procedures? How can this be done safely?

First of all, the appropriate lab techniques must be taught and practiced. For example, students can be shown how to do paper chromatography with one type of marker, and then asked to design a procedure for testing whether all black markers contain the same dyes (or other questions posed by the instructor or students).

The focus is not so much on the specific lab steps as on the scientific method, and how the students will manage the variables and controls in order to collect reliable data. The teacher must still include safety precautions regarding the chemicals and equipment involved, even though the procedures are created by the students. It is essential that the teacher be aware of the possible hazards inherent in a lab before asking students to create procedures for themselves.

In my AP class, students are asked to find the percentage of water in a hydrate. Rather than giving them a procedure to follow, I ask the students to write a procedure based on this question: How can the formula of a hydrate be determined in the lab?

Students’ proposed procedures must be approved before experimentation; if you do not teach on a block schedule, this is best done the day before the lab. Creating their own procedures forces students to think about what data to collect. You will hear them asking each other questions such as, “Do we need to mass it before we add the hydrate?” Instructor guidance is essential in helping students realize that there may be variables which they have not considered, but that nevertheless need to be controlled. If certain steps are wrong, incomplete, or missing, I ask the students leading questions rather than telling them what to do: “How will you make sure it heats evenly?”, “How will you prevent water from re-entering the salt?”, “How will you know that the water has all been removed?”, and so on.

A potential downside of this sort of modification is that students may end up performing the lab incorrectly, which can add stress when you are already on a tight schedule. For example, my students once tried to accelerate the cooling of a crucible with a damp paper towel, which resulted in the crucible cracking. They had to start over. I told them, experiments sometimes go awry; this is the way real science works. It was stressful, but it was an experience they never forgot.

Valuing science: Data collection

Data collection is an aspect of laboratory work that can easily become mindlessly routine for students. They can end up just writing down numbers in tables. In order for students to be engaged, they need to see value in the collection of data and feel responsible for data collection decisions.

In order to accomplish this, I have modified Flinn’s Reaction in a Bag4 to teach signs of a chemical change as well as the scientific method. Students observe what happens when chemicals are mixed in a plastic baggie, and then are challenged to figure out what causes the various changes they saw. They come up with questions about what caused the changes seen in the demonstration, and then divide the possible tests amongst themselves.

Sometimes, the students rather selfishly test only what they want to test (often, whatever combinations the students think will be the most exciting or “cool”), which can lead to some combinations remaining untested. When they report their results to the rest of the class, it becomes clear that without a clearly communicated division of labor, the collected data and results may be incomplete, leading to an inability to answer fully the questions they originally posed. This experience provides a powerful lesson about the value of collecting reliable data and the importance of working together as a team in science.

Valuing science: Communicating, exploring, and predicting

A related way to modify a lab is to have students make predictions before they do an experiment, then present their findings to the class. Students take the responsibility for making predictions rather than confirming something told to them by their instructor. The predictions can be based on material learned in class, or by having students observe phenomena before they learn about the concept in class.

When I teach my students about hydrolysis, I first have them observe and record the pH of various salt solutions. I then coach them to write net ionic equations for each solution in an attempt to explain what is happening to the salts in water. For the lab, students are divided into four research groups, each of which is assigned three salts, for a total of twelve salts (none which are used in the introductory activity). Students predict whether each of their assigned salts will be acidic, neutral, or basic in water, then measure the pH of each with Hydrion paper and universal indicator.

Each group then presents their findings to the class on large posters, showing the net ionic equations and pH levels they recorded. These presentations are key, as each group must explain both their predictions for each assigned salt and whether or not the prediction was supported by the data. Also, students must attempt to explain any data that does not match their predictions or otherwise does not make sense. The net ionic equations on the posters serves as the models for all students to examine as part of their inquiry experience. As their fellow students present, students ask clarifying questions, and record their findings.

During this lab, the students usually observe pH readings shifted to the acidic end of the scale. As the presentations continue, they gradually realize that this is true across all of the groups, and eventually someone realizes that everyone assumed that the deionized water has a pH of 7. This usually leads to a student excitedly jumping up and testing the pH of the water, which is always slightly acidic due to dissolved carbon dioxide from the air. This allows students to experience first-hand the value of communicating with other groups; in this case, they discover an unexpected variable affecting all of their data.

Although this lab is not completely open-ended, the students’ engagement is enhanced by the fact that they are responsible for the predictions, data collection, presentations and, most importantly, discussion of discrepant events.

Closing thoughts

Modifying labs to include elements of inquiry learning need not take a lot of time, either in the writing or the performance of the lab. I encourage you to modify some of your existing labs to present students with interesting phenomena that can spark questions, or guide them as they create their own laboratory procedures. Start by choosing a confirmation lab that you currently use and add at least one element of inquiry to it. Share your experience by starting a discussion about your experiences on the AACT website. I look forward to hearing about your experiences and insights!

References

  1. National Science Teachers Association. NSTA Position Statement: Scientific Inquiry. http://www.nsta.org/about/positions/inquiry.aspx (accessed March 19, 2017).
  2. Colburn, A. An Inquiry Primer. Science Scope. 2000, 23(6): 42–44.
  3. Bracken, J.; Bernstein, J.; Price, P. Inquiry Problem Based Laboratory Experiments. Presented at Inquiry Based AP Chemistry Workshop, North Miami, Florida, November 16, 2013.
  4. Flinn Scientific. Reaction in a Bag. https://www.flinnsci.com/reaction-in-a-bag/dc91419/ (accessed June 17, 2017).

Additional References

American Association for the Advancement of Science. Benchmarks for science literacy; Oxford University Press: New York, 1994.
Just Science Now. http://www.justsciencenow.com/inquiry/ (accessed Oct 21, 2017). Marandola, C. Community College of Rhode Island’s page on Analysis of a Hydrate.
http://faculty.ccri.edu/cmarandola/Chemistry/CHEM%20LABS/Chemistry%20Lab%20Analysis%20of%20a%20Hydrate_Web.htm (accessed June 17, 2017).
Holmquist, D.; Volz, D. Chemistry with computers: chemistry experiments using Vernier sensors. Vernier Software and Technology: Beaverton, OR, 2003.
National Research Council. National science education standards; National Academy Press: Washington, DC, 1996.


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