phd thesis discussion and conclusion

The PhD Discussion Chapter: What It Is & How To Write It

Sep 11, 2023

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Your PhD discussion chapter is your thesis’s intellectual epicenter. Think of it as the scholarly equivalent of a courtroom closing argument, where you summarise the evidence and make your case. Perhaps that’s why it’s so tricky – the skills you need in your discussion chapter aren’t skills you’ve likely had to deploy before: it’s where you start to speak like a Doctor.

In this guide, I want to present a comprehensive guide to the PhD discussion chapter. We’ll look at a number of key topics:

What is the purpose of a PhD Discussion Chapter?

Suggested outlines for a discussion chapter:

Advice for improving your discussion chapter

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The PhD discussion chapter is the place where your findings, research questions, literature, theoretical framework and methodology coalesce into a coherent narrative. A common pitfall is when students see the discussion chapter as a summary of everything that has come before. This isn’t the case. Instead, the PhD discussion chapter offers a deep, analytical synthesis of your research, providing context, interpretation, and evaluation of your findings.

It’s the place in which you engage with existing theories, explore the significance of your work, and directly address the “So What?” question, highlighting the real-world implications and academic contributions of your research.

Let’s dig down into each of these things.

Summarising and explaining the research

Before you launch into the detail, start by laying out your findings in a clear, easy to follow way. This is typically done in the introduction and the first proper section of the chapter.

Starting the PhD discussion chapter by clearly laying out your findings serves as an anchor for your reader and sets the stage for the more complex discussions that follow. This foundational step ensures that the reader is equipped with all the necessary information to fully grasp the significance and implications of your work. It’s akin to laying the groundwork before building a complex structure; without a solid base, the intricate analyses may lose their impact or be misunderstood.

For example, if you’re a PhD student in environmental science studying the effects of a specific pollutant on marine life, begin by presenting the key data points, such as the pollutant concentration levels in various regions and the corresponding health indices of marine species studied. Use tables, figures, or graphs to help visualise the data and make it more accessible.

Laying out Quantitative Findings : If your research is quantitative, use statistical measures to present your results. Clearly state the metrics you’ve considered, such as means, variances, p-values, etc., and what they imply about your research question.
Laying out Qualitative Findings : In case of qualitative research, such as ethnographic studies or interviews, narrate the trends, patterns, or themes that have emerged. Use representative quotes or observations as illustrative examples.
Mixed-Methods Approach : If you’ve used both quantitative and qualitative methods, start by outlining how these different types of data will be integrated in your discussion. This could involve presenting the qualitative findings as a contextual backdrop for quantitative data or vice versa.

Remember, your objective at this initial stage is not to overwhelm the reader with complexity but to build a transparent, easily-followable narrative of what you’ve found. By starting with a clear presentation of your findings, you’re laying the groundwork for a powerful, credible discussion chapter that can tackle sophisticated analyses and weighty implications, underpinned by a comprehensible and compelling dataset.

There will be a necessary degree of overlap and repetition between this section (and the discussion chapter in general) and the findings chapter. However, there’s a subtle difference in the way in which the data is introduced in the findings and discussion chapters .

In the findings chapter, you’re generally presenting raw data or observations without interpreting what they mean. In the Discussion chapter, you take those same findings and begin to explore their implications, relate them to existing theories, and evaluate their significance. The danger, however, lies in creating excessive repetition between the two chapters, which can fatigue the reader and dilute the impact of your arguments.

To mitigate this, consider employing the following strategies:

Selective Highlighting : Choose only the most critical findings to revisit in the Discussion chapter. You don’t need to regurgitate every data point, only those central to the questions you aim to answer in this chapter.
Narrative Framing : When you bring up a finding in the Discussion chapter, introduce it as a stepping stone to a broader point or argument, rather than an isolated fact. This technique helps the reader understand why you’re revisiting this information and what new aspects you’ll be unveiling.
Use Different Presentation Formats : If the Findings chapter is heavy on tables and figures, consider summarising key points in a narrative form in the Discussion chapter or vice versa.

By thoughtfully selecting what to revisit and framing it within a new context, you can transform what might appear as repetition into a coherent and evolving narrative that adds value to your thesis. Read more about the difference between the findings and discussion chapters here .

Interpreting and Contextualising Results

It’s in the discussion chapter that you offer the interpretation and context for your research findings.

Here, you transition from being a data ‘gatherer’ to a data ‘interpreter’, weaving together the threads of research questions, data, methods, literature and theory to tell a complex story. While the Results chapter may offer the “what,” the PhD discussion chapter sheds light on the “why” and “how.”

For example, if you’re a social scientist studying the effects of social media on mental health, your results chapter might show statistical data indicating a correlation between social media use and anxiety. However, it’s in your discussion chapter that you would compare these findings to existing literature, perhaps linking them to existing theories or debates. This adds a layer of depth and context that transcends the numerical data, inviting academic dialogue and potential future research avenues.

There are three ways in which you can synthesise your findings:

Interpretation : Begin by interpreting your findings. Use comparisons, contrasts, and correlations to explain the significance of the results. This is where you should also address any unexpected outcomes and explain them.
Contextualisation : After interpretation, provide a context to situate your findings within the existing body of knowledge. Link back to your Literature Review and Theoretical Framework to show how your research aligns with or diverges from previous work. More on this below.
Evaluation : Finally, critically evaluate your own research. Discuss its limitations, the implications of your findings, and offer recommendations for future research.

Whether you’re in natural sciences exploring a new chemical compound or in humanities dissecting a piece of classical literature, the discussion chapter is your opportunity to show that your research not only answers specific questions but also contributes to a wider understanding of your field. It’s not enough to say, for instance, that a new drug successfully reduced symptoms of depression in 60% of study participants. You must explore what that 60% means.

Is it a statistically significant improvement over existing treatments?
What might be the physiological or psychological mechanisms at work?
Could your research method have influenced these outcomes?

There’s an art to explaining and synthesising your findings [Link to “How to Explain Your Findings”], but think of it this way: this is where you shine a light on the ‘why’ and ‘how’ of your findings, delving into the nuances that raw data can’t express.

Evaluating Existing Theories and Models

Beyond explaining your findings, the PhD discussion chapter allows you to evaluate the existing theories and models that you’ve cited in your literature review and/or theory framework chapter (not sure of the difference? Click here) . Your results could either reinforce established theories or challenge them, both of which significantly contribute to your field.

For instance, did your research on renewable energy technologies confirm the economic theories suggesting that green energy can be cost-effective?
Or did your social research provide empirical evidence that contradicts widely held beliefs in your field?

The PhD discussion chapter therefore serves as the space where the theories, concepts, ideas and hypotheses that make up and informed your theory framework and which you touched upon in your literature review intersect with the empirical data you’ve presented.

You’re not just mapping your findings onto the theories and models; you’re dissecting them, affirming or challenging them, and potentially even extending or refining them based on what you’ve discovered.

For instance, if you’re working on a thesis in psychology concerning cognitive development in early childhood, your Literature Review may have discussed Piaget’s stages of cognitive development. However, let’s say your findings indicate some nuances or exceptions to Piaget’s theories, or perhaps children in a certain demographic don’t follow the stages as previously thought.

Your discussion chapter is where you can make the argument that perhaps Piaget’s model, while generally accurate, might require some modification to account for these cases.

Affirming Theories : If your data aligns closely with the existing theories and models, the PhD discussion chapter serves to strengthen their credibility. Here, you’re lending empirical support to theoretical frameworks.
Challenging Theories : Alternatively, your findings might contradict or challenge the prevailing theories. This is not a shortcoming; instead, it opens the door for re-evaluation and progress in the field, which is just as valuable.
Extending or Refining Theories : Perhaps your research uncovers additional variables or conditions that existing models have not accounted for. In such cases, you’re pushing the envelope, extending the current boundaries of understanding.

As you evaluate existing theories and models, be comprehensive yet nuanced. Draw on varied disciplines if relevant. For example, if your thesis is at the intersection of public health and social policy, integrate models from both fields to offer a multi-faceted discussion. Being interdisciplinary can make your discussion richer and more impactful.

Ultimately, the discussion chapter offers you a platform to voice your scholarly interpretation and judgment. You’re participating in a broader academic dialogue, not just narrating your findings but positioning them in a web of knowledge that spans across time, disciplines, and viewpoints.

Discuss Unexpected Results

The discussion chapter is where you also discuss things that didn’t quite work out as planned. In particular, results that were unexpected.

Sometimes the most perplexing data offers the most valuable insights. Don’t shy away from discussing unexpected results; these could be the starting points for future research or even paradigm shifts in your field.

When your research yields findings that diverge from established theories or commonly held beliefs, you’re offered a unique opportunity to challenge and extend existing knowledge.

Take the field of primary education as an illustrative example. Assume you’re researching the efficacy of a specific teaching methodology that prior studies have lauded. However, your data reveals that while the method works wonders for one subgroup of students, it fails to benefit another subgroup. Far from diminishing the value of your research, this unexpected outcome presents an exciting opening. It beckons further inquiry into why the teaching methodology yielded disparate impacts, which could eventually result in more tailored and effective educational strategies.

In the realm of scientific discoveries, the significance of unexpected results cannot be overstated. Alexander Fleming’s accidental discovery of penicillin originated from what appeared to be a ‘failed’ experiment, but it revolutionised medicine. Similarly, the unintended discovery of cosmic microwave background radiation provided pivotal support for the Big Bang theory. In both instances, what seemed like anomalies paved the way for transformative understanding.

The first task when you encounter unexpected findings is to set them apart from the expected outcomes clearly. Delineate a specific section in your discussion chapter to delve into these anomalies, affording them the attention they merit.

Next, engage in hypothesising why these peculiarities emerged. This could be the point where your years of study and your depth of understanding of your subject really shine. Are there confounding variables that weren’t initially apparent? Could there be an entirely unexplored underlying mechanism at play? Take your reader on this exploration with you, and offer educated guesses based on your literature review and study design.

Lastly, don’t forget to consider and discuss the wider implications of these findings. Could they potentially refute longstanding theories or present the need for a shift in the prevailing school of thought? Or perhaps they hint at previously unthought-of applications or solutions to existing problems? Reflect on how these unexpected results might fit into the broader academic conversation and where future research might take these findings.

By earnestly and transparently tackling unexpected results, you exhibit a commitment to rigorous academic research. The willingness to entertain complexity and to follow the research—even when it leads in unpredictable directions—is a mark of scholarly integrity and courage. This holds true irrespective of your academic discipline, from the humanities and social sciences to STEM fields.

Answering the “so what?” Question

In your findings chapter you would have presented the data. In the discussion chapter, you answer the ‘so what’ question. Make sure to address it explicitly. Why does your research matter? Who benefits from it? How does it advance the scholarly discourse?

As a PhD student, you’ve already invested a substantial amount of time and effort into your research. Therefore, it’s crucial to articulate its importance not only to validate your own work but also to contribute meaningfully to your field and, in some cases, to society at large.

Answering the “so what?” question means connecting the dots between your isolated research findings and the larger intellectual landscape. It requires you to extend your analysis beyond the specifics of your study, considering how it advances the scholarly discourse in your field. For instance, if your research closes a significant gap in the literature, makes a theoretical breakthrough,

Example in Public Health : If your research finds that community-led sanitation programs are far more effective than government-implemented ones, then the “So What?” is clear: policy-makers need to see this data. But that doesn’t mean you don’t still need to discuss it.

Example in Literature : If your research uncovers previously unnoticed patterns of symbolism in 19th-century Russian literature, the “So What?” could be a deeper understanding of how literature reflects societal anxieties of the time.

In order to make your discussion chapter compelling and relevant, it’s imperative to always highlight why your research matters. This goes beyond simply reiterating your findings; you need to connect the dots and show how your research fits into the broader academic landscape. Are you challenging existing theories, confirming previous studies, or offering a new perspective? Establishing the academic importance of your work provides a solid footing for its wider application.

Further to establishing academic relevance, also aim to illuminate the real-world implications of your findings. What are the practical outcomes that could arise from your research? Are there specific scenarios or applications where your research could be a game-changer? For instance, if your study uncovers a more effective method of teaching reading to children with dyslexia, explicitly mention how this could revolutionise educational approaches and improve quality of life for those affected. Providing concrete scenarios enhances the applicability of your research, proving that it doesn’t merely exist in the realm of academic abstraction, but has tangible impacts that can affect change.

Limitations and Future Research

The quest for perfection is more a journey than a destination. This especially holds true in the context of a PhD thesis. Therefore, a well-crafted Discussion chapter should include a section devoted to the limitations of your research, as it establishes the scope, reliability, and validity of your work. Acknowledging limitations is not an act of undermining your research; instead, it embodies scholarly integrity and rigorous academic thinking.

Being upfront about limitations is essentially about being honest, not only with your readers but also with yourself as a researcher. For instance, if you’ve conducted a survey-based study in psychology but only managed to collect a small number of responses, admitting this limitation provides context for your findings. Perhaps the conclusions drawn from such a sample size are not universally applicable but could still offer significant insights into a particular demographic or condition

Do not shy away from discussing limitations in fear that it might weaken your arguments.
Clearly delineate the scope of your research, specifying what it does and doesn’t address.

For example, in a medical research study, if your sample size predominantly consists of individuals from a particular age group, admitting this limitation helps frame your research within that context. Or, if you’re a literature student, if your analysis focuses solely on the works of a single author, your findings might not be generalisable to broader literary trends.

Discussing limitations openly doesn’t devalue your work; it adds a layer of trustworthiness. It assures the reader—and the academic community at large—that you have a nuanced understanding of your research context. It demonstrates that you can critically evaluate your own work, a skill that is paramount.

Your PhD Thesis. On one page.

Example outline for a discussion chapter:.

I’ve included a suggested outline for a PhD discussion chapter. It’s important to note that no two PhDs are alike, and yours may well (probably will) diverge from this. The purpose here is to show how all the various factors we’ve discussed above fit together.

Introduction

Brief Overview of Research Objectives and Key Findings
Purpose of the Discussion Chapter

Summary of Key Findings

Brief Restatement of Research Findings
Comparison with Initial Hypotheses or Research Questions

Interpretation of Findings

Contextualisation of Results
Significance and Implications of the Findings

Evaluation of Existing Theories and Models

How Your Findings Support or Challenge Previous Work
Conceptual Contributions of Your Study
Acknowledgment of Study Limitations
Suggestions for Future Research
Summation of Key Points
Broader Implications and Contributions of the Research
Final Thoughts and Future Directions

Once you’ve navigated through the complexities of your PhD research, you’re now faced with the challenge of bringing it all together in your discussion chapter. While you’ve already considered various facets like summarising findings, evaluating existing theories, and acknowledging limitations, there are some “easy wins”—small, yet impactful steps—that can help strengthen this critical chapter.

The Power of a Well-Structured Narrative

Begin with a well-structured narrative that clearly outlines your arguments. Tell the reader what the destination is at the outset of the chapter, and then make sure each paragraph is a stepping stone to that destination.

Each paragraph should serve a purpose and should logically follow the previous one. This helps in making your discussion coherent and easy to follow.

Use transition sentences between paragraphs to guide the reader through your argument.
Make sure each paragraph adds a new dimension to your discussion.

Data Visualisation Tools

Visual aids aren’t just for presentations; they can provide tremendous value in a discussion chapter. Diagrams, charts, or graphs can provide a visual break and help to emphasise your points effectively.

Use graphs or charts to represent trends that support your argument.
Always caption your visuals and reference them in the text.

Integrate Feedback Actively

It’s often beneficial to have colleagues, advisors, or other experts review your discussion section before finalising it. They can offer fresh perspectives and may catch gaps or ambiguities that you’ve missed.

Seek feedback but also know when to filter it, sticking to advice that genuinely enhances your work.
Don’t wait until the last minute for feedback; give reviewers ample time.

Highlight the Broader Implications

While you’ll delve into this more in your conclusion, don’t shy away from previewing the broader implications of your work in your discussion. Make it clear why your research matters in a wider context.

State the broader implications but keep them tightly related to your research findings.
Avoid making grand claims that your research can’t support

In the journey toward a PhD, learning ‘how to write like a doctor’ is more than mastering grammar or honing your prose; it’s about flexing your academic muscles with confidence and authority. It is in the discussion chapter that you really start flexing, and which you really can and need to speak like a doctor.

For many, this is the first instance of challenging the hegemony of existing literature, refuting established theories, or proposing innovative frameworks. It’s an intimidating task; after all, these are the ideas and research paradigms you’ve been learning about throughout your educational journey. Suddenly, you’re not just absorbing knowledge; you’re contributing to it, critiquing it, and perhaps even changing its trajectory. If it feels challenging, remember that’s because it’s new, and that’s why it’s hard. However, you’ve made it this far, and that alone testifies to your academic rigour and capability. You’ve earned the right to be heard; now it’s time to speak with the academic authority that has been years in the making. So, don’t hold back—flex those academic muscles and carve your niche in the scholarly conversation.