In a previous blog post, I shared my thoughts about the importance of science teachers (and all teachers, really) supporting their claims about lesson efficacy with evidence. While this doesn’t always need to be a formal research study, it can often be valuable to publish findings that will be helpful to other science teachers.
I briefly began to share about a small study I did in my physics classes after I noticed that it seemed my female non-native English speakers were performing particularly well. I’d like to share the details of that study.
I evaluated how English language learners (ELLs) and native English speakers performed on conceptual physics assessments and the extent to which they used models and evidence to justify claims and ideas.
I looked at all of the physics students in two physics sections (53 12th grade physics students in total). These students were enrolled at a small urban public high school where 66% of students qualified for free or reduced lunch programs. The ethnic diversity of the sample was 45% white and 45% Hispanic and the gender diversity was 68% female and 32% male. Of the 53 students, 22% (n=12) were classified as language learners by the school system and these students identified that they did not speak English in their homes. I’m referring to these students as English Language Learners (ELLs).
Student learned physics in a year-long course with Physics and Everyday Thinking (PET), an inquiry- based physics curriculum that is designed to engage students in inductive reasoning and follows a guided scientific model-building approach.
To evaluate concept understanding and growth, I administered the pre- and post-test associated with the PET curriculum at the beginning of the course (August) and end of the course (May). The concept test consisted of nine questions that addressed content from the course, including energy, forces, circuits, and light. I examined the average normalized gain (g-ave) for four subgroups in the course: native English speakers (male and female) and ELLs (male and female).
To evaluate student use of models and evidence, I examined student responses to nine open-ended questions on the cumulative final exam, administered at the same time as the PET post-test. Students were not prompted to use models or evidence in their responses, however, these scientific practices were modeled for students throughout the course.
I considered a “claim” to be a statement that responded to the given assessment question, therefore each question was only coded as having one claim. For the purposes of this study, I defined evidence as an observation used to justify a claim. Evidence could have originated from either a shared observation in class (such as a laboratory finding) or a personal experience outside of class. I defined models as tools that are used to explain why or how a set of phenomena occurs, or to describe a relationship, including a mathematical relationship (formula or written explanation), a graphical representation, or a visual depiction (i.e. force, energy, or light-ray diagrams).
Finding I: Students demonstrated learning gains comparable to university students learning with the same curriculum.
In this study, the mean post-test score was 61% (SD 0.21) and the average normalized gain was 0.54 (SD 0.24). When implemented in 27 semester-long university courses (typically with undergraduate non- science majors), the mean post-test score was 54.2% and normalized gain was 0.4 (SD 0.13).
Finding 2: The extent that students supported their responses with evidence or models correlates with the scientific accuracy of the claims.
When students used both evidence and a model to support their claims, 97% of the claims were scientifically accurate. Conversely, when neither form of rationale was used, only 42% of the claims were scientifically accurate.
Finding 3: Female ELLs demonstrated the most frequent use of models and evidence to support their claims
On average, female ELL students supported their claims (with either evidence or a model, or both) on 8 out of the 9 open-ended questions. This compares to 6.4 for native females, 7.1 for native males, and 5.6 for ELL males. ELL females also most commonly used both evidence and a model to support their claims (an average of 5 occurrences, compared to 3.4 for both native male and native female subgroups and 2.8 for ELL males).
Female students who are not native English speakers, one of the most underrepresented groups in the field of science, excelled when learning physics in an environment that emphasized the scientific practices of collecting and interpreting evidence and building and applying models. This group of students exhibited the greatest gains on the conceptual assessment and the most frequent use of evidence and models to defend their thinking. I observed these students take risks during whole-class discussions by sharing and revising their ideas in front of their peers. An environment that values emotional risk-taking may be the key to these unusual and desirable gains. However, this idea needs to be more carefully studied in future work.
In this learning environment, it was not only the female ELL students who demonstrated learning gains; their peers displayed conceptual growth that was comparable to university students who learned with the same curriculum. Given that the claims were more correct when using evidence, it could be that centering on practices not only resulted in students becoming proficient in using these practices, but also in their physics understanding. I propose two key components of this learning environment that impacted student conceptual growth and use of scientific practices: the inclusive classroom culture and the learning environment that was situated in scientific practice.
I. Classroom Culture: In this physics course, the classroom was a safe place for students to take risks and process through ideas as they evolved on the basis of shared experiences. These norms created a learning environment where students felt that their ideas were worth being heard, even when they were struggling with articulating the scientific principle. It was this discourse community that allowed all students to have access to the science ideas and practices.
II. Learning Environment Situated in Practice: Science, by nature, is collaborative and is a social practice. I suggest that the process of students collecting evidence together created shared experiences and attributed to students becoming included within the learning community. In physics this often involves real, tangible objects that can be discussed, pointed to, manipulated, and moved around. This use of real objects, together with a shared problem to investigate, may greatly facilitate English language learners’ opportunities and abilities to share their thoughts and participate in the classroom community. Additionally, the scientific practice of building and revising models provides a visual means for students to discuss their ideas. I suggest that this helps equalize the opportunities for students and can be responsible for reducing the language barrier. Inclusion, participation, and a sense of belonging may have a drastic impact on English language learners’ future science pursuits.