There are three aspects of science (Figure 1): (1) scientific knowledge: what we know about the natural world, which would include crosscutting concepts; (2) scientific practices: skills and knowledge necessary for building scientific knowledge; and (3) nature of science (NOS): how science works (Bell et al. 2003). Most science instruction emphasizes the importance of scientific knowledge and practices, but NOS is often left out or not explicitly referenced. However, NOS is critical for understanding how scientists develop scientific knowledge across a variety of disciplines and engage in scientific practices. In understanding NOS, students and teachers have a lens to help them understand the practice of science and its relationship to the world around them.

Unfortunately, the lack of NOS instruction in K–6 contexts results in misconceptions being held by students (Herreid, Schiller, and Herreid 2012; Hodson 2008) and science teachers (Lederman and Lederman 2014). These misconceptions include:

• scientists participate in a linear scientific method
• scientific knowledge is complete
• scientists are atheists
• scientific theories are unreliable
• science must be experimental
• observations are always reliable

As our world continues to grapple with important scientific ideas like climate change and COVID-19, understanding how science works and having an accurate view of NOS becomes even more critical for our society.

To develop accurate conceptions of NOS, it is critical that it be integrated within our science instruction. Effective NOS instruction is marked by explicitly and reflectively teaching NOS (Khishfe and Abd-El-Khalick 2002; Lederman and Lederman 2014) as well as teaching it in contextualized (Solomon et al. 1992) and decontextualized contexts (Bell, Matkins, and Gansneder 2011). Explicitly and reflectively teaching NOS means explaining what NOS is to students and providing them with opportunities to think about how NOS applies to their learning experiences. This does not mean simply engaging students in scientific practices; this has been shown to be ineffective (Bell et al. 2003).

NOS instruction can also take two forms: contextualized and decontextualized. Teaching decontextualized NOS is helpful for understanding specific elements of NOS such as the creativity of science. By seeing this element in a concentrated form, students are able to understand the individual idea and apply it to a specific context (Bell, Matkins, and Gansneder 2011). Learning NOS in a contextualized form can also be helpful for developing accurate NOS conceptions (Bell, Matkins, and Gansneder 2011; Solomon et al. 1992). Furthermore, situating NOS within discipline-specific contexts can help students see how NOS applies specifically to what they are learning, and allows teachers to create learning experiences that integrate NOS with content that still needs to be covered.

Appendix H from the Next Generation Science Standards (NGSS Lead States 2013a) provides a matrix of eight themes central to developing an understanding of NOS. All of these themes are connected to specific standards across all grade bands and disciplines to support the development of students’ understanding of NOS over the course of their K–12 education. These ideas are not meant to be a separate part of science instruction but should be embedded within three-dimensional (3D) science instruction. In this article, we describe science portfolios implemented in a high school science class so students could reflect on NOS and examine how their conceptions changed and developed over the year.

Science portfolios

Portfolios are collections of student work that are purposefully selected and allow for student commentary and reflection (Danielson and Abrutyn 1997). It is specifically this reflection element that provides a means for effective NOS instruction. Portfolios also are a form of authentic assessment, allowing students to show what they know and allowing teachers to assess elements of the class that are typically hard to assess (e.g., NOS conceptions). Because portfolios are developed by the students, they allow for differentiated instruction based on student choice, interest, readiness, and learning profile (Tomlinson 1999). Portfolios also provide a way for teachers to generate a better picture of students’ understanding and alternative conceptions while also getting to know the students (Whitworth and Bell 2013).

For students, portfolios can be useful because they offer a framework for looking at the science around them, depict longitudinal growth, provide a means for self-reflection and communication, and personalize students’ achievements (Slater 1997). By utilizing these design elements, the following describes how science portfolios assessing all three aspects of science can be integrated within traditional 3D science instruction to support students’ understanding of NOS.

Portfolio components

The science portfolio described below is a student-selected compilation of work, demonstrating understanding of scientific knowledge, scientific practices, and NOS ideas that are an integral part of my science instruction. Students were introduced to the portfolios at the beginning of the year, had unit (Table 1; see Online Connections) and quarter check-ins (Table 2; see Online Connections) to ensure the work was being completed, and were required to reflect on their goals and understanding of science throughout the year. Disciplinary core ideas (DCIs) are addressed as students select artifacts and reflect on the content learned as it relates to a specific aspect of science.

Utilizing these portfolios generated a picture of student understanding that went beyond the content learned in class and moved into conceptions regarding NOS, science and engineering practices (SEPs), and crosscutting concepts (CCCs). In addition, portfolios address many of the writing English Language Arts Common Core State Standards through the required elements. By combining portfolios with exit tickets, science investigations, projects, and exams throughout the year, we were able to see how students developed in all aspects of science that are necessary for being scientifically literate.

Assessment of the portfolio occurs in multiple phases and with different goals. The elements of the portfolio are assessed when they are initially submitted for content and quality. As we describe each element below, we also provide a rubric for assessing that element. In the second phase, we assess students’ final portfolio using an overall portfolio rubric (Table 2; see Online Connections) that is focused more on students’ revision and inclusion of elements. This final grade assesses whether they have taken the time to revise elements they previously submitted and included it in their final portfolio. Teachers can revise the rubric to focus more on content of the portfolio elements if they’d like, but we felt our approach made the most sense for our students and classroom.

Introduction letter and picture

At the beginning of the year, students wrote an introduction letter to provide an understanding of who they were and what they thought science was. They described their attitudes toward science, documented science classes they have had so far, and addressed goals for themselves in class. Students also included a picture either of themselves or something portraying who they are.

Even though this was one of the first assignments students completed, they added to it over the year as their goals, attitudes, and conceptions of science developed. Each quarter, as students completed self-evaluations, they revised and resubmitted their introduction letters, keeping copies of previous versions for documentation and future reflection. By the end of the year, students were able to provide a thorough description of themselves, their goals from the year, how their idea of science changed from taking this class, and what story they were trying to tell with their portfolio.

This section was helpful for me as the teacher to get to know my students and see how they were processing their growth. This element was included in the final version of the portfolio. A rubric for assessing this element is provided in Table 3 (see Online Connections).

Unit artifacts and caption forms

Two critical elements of the science portfolios were the unit artifacts and caption forms (Appendix A; see Online Connections). For each unit of the class, students selected one artifact for their portfolios demonstrating their understanding of a specific aspect of science. By the end of the year, the students should have at least one artifact representing each of the three aspects of science. Artifacts students choose to include could be excerpts from lab notebooks and summary tables, homework assignments, exit tickets, models, or projects. Each artifact students submitted was accompanied by a caption form that aligned with the aspect of science they chose to highlight.

Students were asked to identify the accompanying artifact, select a specific element of the aspect they chose, and describe how this artifact shaped their understanding of science. For example, one student chose the day where students learned about the language of science and how to differentiate between hypotheses, laws, and theories (Figure 2 and Figure 3). Depending on the story students want to tell with their portfolio, they can either choose artifacts that demonstrate how their understanding of a single idea develops over the year, or they can show a range of growth over the course of the year. From a teacher’s perspective, a more holistic picture of student understanding is valuable, but providing students with exit tickets that strategically showcased specific aspects of science still allowed for the collection of evidence of growth throughout the year.

For example, one student chose to complete a nature of science artifact and caption form for an activity where students analyzed multiple data sets over time to revise their hypotheses and determine parentage for a set of lion cubs (Figure 4 and Figure 5). This activity was never explicitly connected to the idea that science is open to revision in light of new evidence or that scientists use multiple methods, but these concepts were not new to students due to having talked about them earlier in the year. Instead, this student was able to see how these ideas applied to a new context, specifically the disciplines of genetics and zoology.

Reflective essays

Students were also required to complete a reflective essay at the end of each unit. In these essays, students explained how their understanding of science as a whole developed over the past unit in at least one paragraph. By frequently writing these short reflective essays, students started making connections about how all three aspects of science are connected to one another. These essays also serve as a starting place for students’ final reflective essay, and help the teacher and other readers see how students’ understanding develops gradually over the year. For the final reflective essay, students are expected not just to reflect on science as a whole but to also describe the importance of each aspect of science, why it is critical to understand all three separately, and why they work together to provide a better picture of science. Each essay was graded at the end of the unit and included in the final version of the students’ portfolio.

Figures 6 and 7 are examples of the type of essays students submit. We hope it is evident from reading these examples how students’ understanding and thinking grows over time. These essays require students to be metacognitive and sincerely reflect on what they have learned. Through these essays and other assessments, like exit tickets, projects, exams, and the other elements in the portofolio, student growth over the course of a year becomes readily apparent.

Lauren Simpson (lauren.simpson@gocommodores.org) is a science teacher at Lafayette High School in Oxford, MS and Dr. Brooke A. Whitworth (bwhitwo@clemson.edu) is an Associate Professor at Clemson University in Clemson, SC.