Computer science is a field of dual identities. On the one hand, it’s abstract, mathematical, and conceptual. On the other, it’s deeply applied, data-driven, and user-focused. These two identities are reflected in the two primary modes of research in computer science: theoretical and empirical.

At Learn in Europe, we believe that doctoral students should not only specialize in their niche—but also understand the broader landscape of research methodologies. Let’s take a closer look at what defines these two approaches, how they differ, and why both are essential to advancing the field.


📐 What Is Theoretical Research in Computer Science?

Theoretical computer science focuses on foundational questions:
What can be computed? How efficiently? What are the limits of algorithms, systems, or models?

It uses mathematics and formal logic as its primary tools.

🔎 Key Characteristics:

  • Abstract: Concerned with idealized models like Turing Machines, graphs, or formal languages

  • Precise: Often involves mathematical proofs and formal reasoning

  • Timeless: Results are general, reusable, and not dependent on hardware or context

🧾 Example Topics:

  • Algorithm analysis and complexity theory

  • Formal verification of systems

  • Cryptography and secure communication

  • Automata theory and compiler design

✅ Strengths:

  • Produces general truths that apply across time and platforms

  • Lays the groundwork for technological breakthroughs

🚧 Limitations:

  • May be disconnected from practical implementation

  • Difficult to validate through real-world testing


🧪 What Is Empirical Research in Computer Science?

Empirical computer science focuses on observing, measuring, and experimenting with real-world phenomena—whether that’s how users interact with a system or how an algorithm performs under real conditions.

It is based on experiments, data collection, and statistical analysis.

🔎 Key Characteristics:

  • Applied: Often deals with user studies, system performance, or software evaluation

  • Contextual: Results may depend on specific settings or conditions

  • Iterative: Builds knowledge through repeated testing and refinement

🧾 Example Topics:

  • Usability testing in human-computer interaction (HCI)

  • Benchmarking of machine learning models

  • Performance analysis of distributed systems

  • A/B testing in web interfaces

✅ Strengths:

  • Grounds research in actual practice

  • Reveals unexpected issues or behaviors

  • Essential for validating theories and improving systems

🚧 Limitations:

  • Results may not generalize beyond the experiment

  • Dependent on careful design and statistical rigor


🔄 How They Complement Each Other

AspectTheoretical ResearchEmpirical Research
GoalDiscover truths, limits, and guaranteesUnderstand performance and behavior
MethodsProofs, formal models, simulationsExperiments, data collection, analysis
OutputTheorems, models, frameworksFindings, metrics, usability reports
ValidationLogical consistencyReproducible results, significance tests
StrengthUniversality, abstractionPractical insight, context awareness

In reality, the strongest research projects often combine both approaches. You might begin with a theoretical insight, implement a prototype, and then empirically test it. Or you may discover patterns in empirical data that inspire a new theoretical model.


🧠 Final Thought

Whether you're proving the limits of computation or conducting a user study on mobile apps, both theoretical and empirical research are crucial to the growth of computer science. Each approach asks different questions—but together, they push the field forward.

At Learn in Europe, we equip PhD students not only with cutting-edge tools but also with the mindset to bridge theory and practice. After all, it’s at the intersection of the two that true innovation happens.

👉 Ready to expand your research skills? Explore our doctoral training programs here.