How Do I Use Theory in Physics Education Research?

Wonyong Park (University of Southampton)

Originally written July 2023; Revised September 2026

One of the most common questions asked by researchers who are new to physics education research is: how do I use theory in my research?

The question can arise at an awkward point in a project. A researcher may already have an interesting problem, some data, perhaps even findings, and then encounters an expectation that the study should have a “theoretical framework”, whether from your reviewer 2, examiner 2, or supervisor 2. This can make theory feel like something added to a study as a tick box: a named framework introduced in the literature review and returned to briefly in the discussion.

But theory can do much more. Theory helps us decide what we are looking at, what counts as evidence, which relationships are significant, and what would count as an explanation. To see why, it may help to begin not with education research, but with a familiar physics problem.¹

1. A physics analogy

Imagine a ball projected horizontally in a uniform vertical gravitational field, and suppose we record its position at regular time intervals.

At the observational level we can describe some straightforward trends. The ball travels approximately equal horizontal distances in equal intervals of time. Its vertical displacement increases more rapidly. Its path is curved. Measurements give approximately

\(x = ut\ \)and \(y = - \frac{1}{2}gt^{2},\)

so that eliminating time gives

\[y = - \frac{g}{2u^{2}}x^{2}.\]

The trajectory is therefore parabolic.

These are descriptions of what we observe. The parabola, however, does not explain itself. It does not tell us what gravity is, why the horizontal velocity remains constant, or why the vertical velocity changes. For that, we need theory.

1.1 A Newtonian account

In Newtonian mechanics the explanation begins with forces. Once the ball leaves the launcher, the only force acting on it is

\[\mathbf{F} = m\mathbf{g}.\]

And Newton’s second law gives

\(m\ddot{x} = 0\ \)and \(m\ddot{y} = - mg.\)

The absence of a horizontal resultant force explains the constant horizontal velocity; the downward gravitational force explains the vertical acceleration. What we observed as a parabola is now interpreted as the superposition of uniform horizontal motion and uniformly accelerated vertical motion.

1.2 A Lagrangian account

We can describe the same physical system differently. For the ball,

\[L = T - V = \frac{1}{2}m({\dot{x}}^{2} + {\dot{y}}^{2}) - mgy.\]

Applying the Euler–Lagrange equations returns the same equations of motion, and therefore the same trajectory. But the explanatory organisation has changed. Because \(L\) does not depend explicitly on \(x\), the conjugate momentum \(p_{x} = m\dot{x}\) is conserved.

The Lagrangian formulation makes explicit a structural connection that is less apparent in the usual Newtonian force-based presentation: horizontal translation symmetry is associated with conservation of horizontal momentum. The Newtonian account is not inconsistent with this connection, but the Lagrangian formalism brings it to the foreground.

1.3 A relativistic account

General relativity reorganises the explanation again. A freely falling ball is not, fundamentally, being pulled downwards. Once released, it follows a geodesic through spacetime,

\[\frac{d^{2}x^{\mu}}{d\tau^{2}} + \Gamma_{\alpha\beta}^{\mu}\frac{dx^{\alpha}}{d\tau}\frac{dx^{\beta}}{d\tau} = 0.\]

which in the weak-field, low-velocity limit near the Earth’s surface reproduces the familiar \(\ddot{y} = - g.\)

The two accounts assign very different physical significance to the observed acceleration. In Newtonian mechanics the ball’s downward coordinate acceleration is attributed to a gravitational force. In general relativity a freely falling ball has zero proper acceleration, while the laboratory floor, prevented from following a geodesic, has nonzero proper acceleration.

Observations, in other words, do not arrive with explanations attached. Theory makes particular features of what we observe meaningful, and can change what we take the observation to be.²

2. From projectile motion to the physics classroom

Now consider a common physics education scenario.

A researcher records an introductory physics class and notices that one student, Maya, rarely volunteers answers during whole-class questioning. When called on, she gives short responses. During small-group problem solving, however, she speaks frequently, develops detailed explanations, and sometimes corrects her peers’ reasoning.

We might begin descriptively:

• Maya contributes infrequently during whole-class interaction;

• her whole-class responses tend to be short;

• she contributes much more extensively during group work;

• her participation therefore varies systematically with instructional context.

This is useful empirical work, and observations at this level can be genuinely informative, particularly when collected at scale. But just as a parabolic trajectory does not tell us why the ball moves as it does, these observations do not tell us what Maya’s pattern of participation means.

Each of the three possible accounts below could be pursued through quantitative, qualitative or mixed methods; theories constrain method to varying degrees, but few of them determine it.

2.1 A self-efficacy account

Suppose we approach the problem through self-efficacy theory. We might ask whether Maya’s willingness to participate depends on her beliefs about her capability to perform successfully in public. Whole-class questioning carries a greater perceived risk of being wrong in front of an audience, whereas small-group discussion offers a lower-stakes setting. The chain we are proposing runs roughly:

prior experiences of success and failure → self-efficacy beliefs → perceived risk of a setting → observed participation

This shapes what we collect and what would count as support for the account. We might interview Maya about how confident she felt at particular moments in the recording, administer a physics self-efficacy measure, or compare her participation across tasks that differ in evaluative pressure while the group is held constant. Evidence against the account would look like consistently high reported confidence alongside continued silence. Through this process, the observation “Maya does not speak very much” acquires a psychological meaning.

2.2 A sociocultural account

The same classroom can be analysed through a sociocultural perspective. Participation is no longer treated primarily as the expression of something inside Maya. We ask instead how different structural and interactional conditions make different forms of participation possible.

Perhaps whole-class discussion is organised around rapid teacher questions, short answers and immediate evaluation, whereas group work allows students to develop an idea over several minutes without adjudication.

The analysis turns to the interaction itself: who allocates turns, how long the wait time is, how long a turn may run before it is closed down, whether an incomplete idea can safely be offered, and whose contributions are taken up and built on. The important phenomenon may then not be Maya’s “low participation” at all. The more productive question could be: how do different classroom structures enable or constrain participation in physics? In this theoretical framing, Maya’s extensive group talk becomes central evidence that her participation is situated.

2.3 An identity and recognition account

A third researcher might approach the same episode through physics identity, positioning and recognition. Now we ask: who is recognised in this classroom as a competent physics person? Who is expected to answer difficult questions? Whose explanations receive uptake from teachers and peers? How does Maya position herself, and how is she positioned by others?

Perhaps another student has gradually come to be treated as the class’s physics expert during whole-class interaction. Maya may contribute equally sophisticated reasoning in small groups and receive little public recognition for it. The relations under study are something like:

participation → recognition by others → identity as a physics person → further participation

This account also brings in something the other two leave out. Recognition is not distributed randomly. Who is heard as sounding like a physicist, and who has to work harder to be heard that way, patterns along lines of gender, race and class. I have deliberately said almost nothing about Maya beyond her name, but a researcher working with these theories could not leave such details out, because for this account they are part of the explanation rather than background to it.

Again, the theory is not merely supplying terminology for the discussion section. It changes what the researcher attends to in the video, what further evidence is needed, and what counts as an explanation.

3. What theory actually does in PER

Theory tells us what to notice. One researcher notices confidence, another turn-taking, another recognition, another institutional norms.

It specifies what kinds of things exist in our explanations. Depending on the theory, our analytical world may contain beliefs, identities, practices, norms, discourses, resources, communities, structures or forms of capital.

It proposes relationships among them. We may theorise that self-efficacy influences persistence, that participation contributes to identity formation, or that particular classroom practices distribute opportunities for recognition unevenly.

It determines what would count as evidence. A self-efficacy explanation may require interviews or survey measures; an interactional explanation may demand fine-grained video analysis; a structural account may require information reaching well beyond the immediate classroom.

Importantly, theoretical choices distribute responsibility. If we explain Maya’s silence as low confidence, the problem is located in Maya, and the intervention will be designed to change her. If we explain it through participation structures, the problem is located in the design of instruction, and it is the teaching that changes. If we explain it through recognition, the problem belongs to the classroom’s distribution of credibility, and the question becomes who is publicly positioned as competent in physics and who is not. All three accounts are compatible with the same video recording; They are not compatible with the same politics.

Theory therefore underpins the research questions we ask, the data we collect, the analysis we conduct, and what we take our findings to imply for practice (Stalmeijer & Varpio, 2026).

4. Do I always need a theory?

You may already be using theory in your research without realising it. Even what we take to be a purely empirical observation is rarely theory-free. The simplest descriptions, such as “constant speed” or “Maya’s contribution was short”, rest on assumptions about what is worth noticing, what should be measured and how it should be observed. This is the theory-ladenness of observation (Hanson, 1958). In that sense every PER study carries theory, whether or not it is named. Terms such as self-efficacy, achievement, identity, social norms and effectiveness each arrive with a web of theoretical commitments already attached.

Theory use is therefore a matter of degree rather than a simple yes or no, and more theory, or heavier use of it, does not necessarily make a better study. I have recently published papers of both kinds. In one (Park, 2026), the presentation of findings was deliberately inductive because I wanted students’ peer-directed experiences and emotions to remain alive on the page. This allowed me to develop knowledge that I think is more interesting and relevant to practitioners. In another (Park & Ha, 2026), things were more complicated: as we worked through the data, we realised that several concepts, and the relationships between them, were needed to do justice to what was happening in these preservice teachers’ lives. We therefore drew heavily on a sociological theory of how individuals act within structural conditions (hence the substantial ‘theoretical framework’ section) and it allowed us to see and explain more than a minimal framing would have. Either study could have been written the other way round, but neither, I think, would have been as good.

The caution, then, is about coherence rather than quantity. A theoretical framework should do more than appear in the literature review, disappear for twenty pages, and return in time for the discussion. Whatever the level of theory, it needs to run through the research questions, data collection, analysis, presentation of findings and interpretation. Returning to Maya, if the question you ask is individual-centred and the evidence you gather is mostly about Maya herself, a structural account of what you found cannot be adequately carried by the study you actually conducted, however appealing that account may be.

5. Questions for reflection

As you think about theory in your own research, it may help to step back from the question of which named framework to use and ask what your theoretical choices are actually doing.

• What assumptions are already built into the way I have defined my research problem and described what I observe?
• What does my theoretical framing make particularly visible, and what might it push into the background?
• If I used a different theoretical perspective, how might my research question, data collection or interpretation change?
• Where does my explanation locate responsibility: in individuals, interactions, institutions, structures, or somewhere else?
• Is the theory I use genuinely shaping the study, or have I mainly added theoretical language to findings that were produced independently of it?
• Do my research questions, evidence, analysis and conclusions tell a coherent theoretical story?

6. References

Hanson, N. R. (1958). Patterns of discovery: An inquiry into the conceptual foundations of science. Cambridge University Press.

Park, W. (2026). “Be better than you need to be”: A-level Physics students’ rants, resilience and peer pedagogy on TikTok. Research in Science Education. https://doi.org/10.1007/s11165-026-10332-x

Park, W., & Ha, H. (2026). Testing times: A structure/agency perspective on becoming a science teacher in a competitive, exam-based teacher selection system. Science Education. https://doi.org/10.1002/sce.70096

Stalmeijer, R. E., & Varpio, L. (2026). How to incorporate theory in qualitative research: AMEE Guide No. 183. Medical Teacher, 1-16. https://doi.org/10.1080/0142159X.2026.2614604