COMPUTER SCIENCE

An extended essay in computer science is a technical investigation grounded in computational principles. It differs from essays in other subjects by demanding conceptual depth in relation to computer science, structured methodology and critical analysis of systems, algorithms or technologies. Your essay in this subject must maintain a clear academic focus on how and why computational systems function as they do.

The central expectation is that the essay explores a contemporary computing problem through a computer science lens. This might involve investigating how a specific machine learning algorithm performs under certain conditions, evaluating the security of a cryptographic protocol, or comparing algorithmic efficiency across different datasets or scenarios. Strong essays are distinguished by the application of relevant theory, a focused research question and technically appropriate research methods.

You must distinguish your extended essay in computer science from the internal assessment (IA). Whereas the IA focuses on developing a software product, the extended essay is an academic research paper. You may write code, build systems or run simulations as part of your investigation, but these elements must serve the research question, not drive the essay. Additionally, you are not permitted to reuse data or outputs from your IA. For instance, designing a chatbot would not be a valid extended essay topic on its own. However, using original experiments to compare the performance of two natural language processing models in chatbot responses could be appropriate. Essays based on secondary data or a literature review are equally valid when conducted with academic rigour. Descriptive overviews or journalistic summaries are insufficient. Instead, you should apply a clear and consistent methodology, such as comparative analysis, technical evaluation or algorithmic benchmarking. Strong essays identify meaningful criteria, assess the strengths and weaknesses of existing approaches, and build a coherent argument supported by scholarly sources. Importantly, the rationale for selecting a research topic must be grounded in academic literature.

Care must be taken to ensure that your topic is appropriate for computer science. Essays that centre on

historical trends, financial analysis, business case studies or the social effects of technology may be more

suited to other subjects, such as digital society, economics or psychology. Ethical or social considerations

may be briefly addressed—for example, in the introduction or conclusion—but they should not dominate

the analysis.

Make sure you avoid overly broad research questions. For instance, “How effective is encryption?” is too

general. A more appropriate question would focus on a specific encryption algorithm under defined

conditions, such as “To what extent does AES-256 maintain performance and security under varying key

sizes and input volumes?”. This narrow scope makes it possible to conduct meaningful analysis, apply

technical methods and reach defensible conclusions.

You should choose a topic that allows for analysis through computer science principles, such as algorithmic

complexity, system performance metrics or computational theory. While interdisciplinary links may be

present, the essay must remain rooted in the discipline of computer science.

When selecting a topic, you should consider recent developments in computing, the availability of data or

models, and guidance from academic sources. Strong research questions often emerge from identifying a

gap in existing literature, comparing established methods or assessing performance under defined

constraints.