Conceptual understanding, according to Koniceck-Moran and Keeley (2015), is a more thorough comprehension of a topic that extends beyond short-term, rote memorization. In their NSTA publication, Teaching for Conceptual Understanding in Science, the authors make reference to baking a cake from scratch. Any novice can follow a recipe to make a cake, but true mastery involves knowing how each ingredient contributes to the whole. Teaching toward such an ambitious goal requires us to meet the students “where they are at” in terms of their pre-existing knowledge. A teacher will promote enduring student comprehension if he or she is able to capitalize on what a child already thinks they know about a scientific phenomenon. 

Building on student ideas, particularly ones that are erroneous, is a critical aspect of the instructional process. It allows us to use students’ prior knowledge as a foundation to a more personalized and lasting grasp of how a scientific phenomenon works. This lesson progression addresses a common misconception connected to the standard MS-PS1-4: Develop a model that predicts and describes changes in particle motion, temperature, and state of a pure substance when thermal energy is added or removed (NGSS Lead States 2013). The strategies communicated here might be applied to other discrepant events as well.

Engage

Using student prior knowledge to build a more complete learning experience requires that we first identify those concepts that students struggle to grasp. Fostering a culture in which students can discuss scientific ideas, as a whole class or in small groups, has tremendous value. Providing learners opportunities to talk about what they observe, without fear of being evaluated, can give insight on where to take instruction that will follow. When we hear our students talk about what they observe, those critical misunderstandings may be revealed. While I was preparing to address standard MS-PS1-4, I remembered in years past that students were stumped by the question, “What is inside of the bubbles when a pot of water is boiling?” To gain more information on the ideas held by learners in my classroom, I presented the students with a simple system: a beaker filled with water, a thermometer, and an electric hot plate. The students observed the teacher demonstration of boiling water with the mandatory use of goggles. An apron and insulated gloves are also recommended safety precautions. (Note: Studentsmight also boil the water using electric hot plates in small groups, provided that expectations have been set regarding the safe handling of hot glassware and liquids.) As the system reached boiling, I asked learners to journal and draw labeled sketches in response to the following questions: What is happening here? What do you think is inside of the bubbles? The students were given time to think, write, revise, and independently express their thoughts as thoroughly as possible. 

In the same class period, I extended the investigation to a small group-sharing session, and eventually a whole-class conversation. In this preliminary stage, I simply wanted the kids to tell me what they think they knew about the boiling process. I guided the conversation along with phrases such as: “[Student A], do you agree with what [Student B] stated? [Student C], can you tell me what you think [Student A] is trying to say in your words?”

I also made mental notes of student ideas that were shared. It was extremely important that I not interrupt the investigative process by simply giving the “correct” answer away. I wanted to provide an experience for learners to persevere and struggle to gain clarity on a phenomenon that is complicated to understand. During the class discussion, I noticed two popular, erroneous explanations of the boiling process: (1) the bubbles contain “air” (specifically oxygen gas that is released into the room) and (2) the bubbles contain hydrogen and oxygen gas that have been released by the breaking of bonds that hold the two elements together. At this point I wanted to gain a more systematic read on my student population. Do all of my students believe these ideas, or only the ones that are most vocal during our class discussion? 

Explore

Once I had confirmed my suspicion that students were unclear on the boiling process, I wanted to utilize a tool to document each student’s current level of understanding more completely. The “Keeley probe” method of formative assessment presents learners with a mysterious natural event, offers reasonable explanations for the event, and asks learners to justify why one explanation is superior to the others. Keeley offers myriad premade formative assessment probes through publications such as the Uncovering Student Ideas series (Keeley and Tugel 2009), I felt that it was necessary for me to revise Keeley’s “what’s in the bubbles” probe to suit the needs of my learners. 

To effectively track each student’s preconceived ideas about boiling water, I created a Google form (Figure 1). In the form, I describe a relatable event in which a boy has questions about the boiling process while his father cooks dinner. In the prompt, the students are asked to choose an explanation that is the most scientifically accurate. I believe a key to developing a worthwhile prompt is to offer potential explanations that are both reasonable and logical. An advantage to creating my own assessment prompt is that I was able to incorporate student misconceptions that I overheard in our initial discussion of the topic. 

The critical aspect to a formative assessment probe is the requirement for students to explain their thinking. While a student can simply choose any of the suggestions through pure guesswork, that learner must expand on their thought process more completely in their justification. These student responses were invaluable. Not only did I have a clear picture of exactly how prevalent the misconception was, but I also could look to the student explanations when brainstorming ways to troubleshoot the erroneous beliefs. Reading responses were very enlightening. It was interesting to note that most of my eighth-grade students did not know that water vapor filled the bubbles during the boiling process.

Explain

After analyzing student responses, I asked myself the question: How can I encourage my students to observe the boiling process more analytically—so they can see firsthand what is coming out of the bubbles? I decided to video record a boiling beaker of water using the slow-motion feature on my phone. I uploaded the 15-second video clip to my Google drive and brought the media to my next class. It was at this point in the lesson set that I asked groups of learners, five or six at a time, to join me in front of my computer. Before showing the video, I shared that one member of the group had correctly identified the most scientifically accurate statement regarding the boiling process. The student group immediately wanted to know which member of the group was right, but I purposely did not honor the request. This struck me as the critical moment in the learning process. The students were hooked. They were coming to terms with the fact that their existing schema for how the natural world works, their experience-based framework, had proven itself to be insufficient. I could simply give the right answer away, as I explained to my student group, and the entire experience would be quickly forgotten. I instead challenged students to construct a new understanding that is based on observation and critical thinking. This is an arduous process, as the rebuilding of conceptual understanding requires a considerable amount of risk taking and uncertainty. 

Once the small student group was primed to observe the elusive phenomenon again, I showed a clip of a beaker of boiling water heated with a hot plate (see Figure 2). The “slow mo” feature accentuated details of the process that might be overlooked at normal speed. The manipulated clip allowed the viewer to pay closer attention to the bubbles of steam permeating the water. Specifically, a viewer could more easily see where the bubbles originated and the contents of the bubbles once they break the surface of the water. We used technology to enhance our ability to critically examine and draw inferences from a natural event. I promoted learner analysis of the system with guided questions that included: “Where do the bubbles start? Where in the beaker are the bubbles forming? Where do the bubbles seem to be heading toward and what appears to be coming out?” Learners who previously held onto ideas such as “air is trapped in water and it is released during boiling” (a sample student response) must confront the observation that bubbles form strictly near the heat source and emit steam when they pop at the liquid’s surface.

Elaborate

After students had acquired a working understanding of the boiling process (i.e., that water vapor forms near the heat source and erupts from the surface of the liquid), they were encouraged to elaborate on that concept through more traditional study of heat, temperature, and particle motion. I utilized interactive websites to help learners visualize the relationship between heat and particle motion. Our school district purchases a yearly subscription to Explorelearning.com, and dynamic Gizmos such as “Phases of Water” accurately model the relationship between heat and particle movement. I also incorporate free online resources like CK-12.org and OpenSciEd.org into my follow-up lessons. CK-12.org provides content in the form of expository text and engaging videos. OpenSciEd.org offers coherent lesson sequences that faithfully represent the three-dimensional standards. This traditional instruction of content could cover anywhere from three to five class periods.

Evaluate

A compelling sign of student learning is a child’s ability to reflect on how their thinking has developed and changed over time (Mallozi and Heilbronner 2013). The introductory “Keeley probe” provided a valuable glimpse into the student’s thinking process. It has the added benefit of offering a snapshot of a student’s thinking at one specific point in time. After they were given an opportunity to expand their knowledge through exploration of content, students were often surprised to read their original responses to the question prompt. It is worthwhile for learners to not only recognize changes in their thinking, but also be able to spot and articulate specific weaknesses in a scientific argument. Such skill sets will allow learners to engage in their world as adults with the capacity to think critically. In this activity, I asked students to demonstrate their learning through an argument that follows the claim, evidence, and reasoning (CER) format. Learners would construct a response to the central question “What is inside bubbles during boiling?” and utilize evidence to substantiate their claim.

Conclusion

Instruction that is prescriptive and driven purely by coverage of content fails to capitalize on teachable moments that may present themselves. A simplified, undifferentiated “one size fits all” teaching approach does not take a child’s prior experience and current understanding of the natural world into consideration. By being receptive to student misconceptions before delivering instruction, we hone our ability to troubleshoot specific areas of confusion and build on existing belief systems to promote more lasting retention of scientific ideas. •

Shawn Sutton (ssutton@wtschools.org) is a middle school science teacher at Washington Township Schools in Long Valley, New Jersey.