How to do a literature search

A literature search is the structured process of finding the publications that matter for your research question. In practice it means breaking your topic into a handful of concepts, translating those concepts into search terms, running them in suitable databases, screening the results and keeping a record of what you did. Done well, it takes a few focused sessions rather than weeks of random browsing.

Step 1: Start with a working question

You do not need a final research question to begin, but you need a direction. Write down one or two sentences describing what you want to find out. From that sentence, pick out two to four core concepts. For “How does remote teaching affect student engagement in first-year engineering courses?” the concepts would be remote teaching, student engagement and engineering education.

If the question is still vague, the guide on formulating a research question helps you narrow it before you spend hours searching.

Step 2: Build a vocabulary for each concept

Every concept has synonyms, related terms, spelling variants and sometimes a technical term used in the literature. Collect them in a simple table:

Concept	Synonyms and variants
Remote teaching	online teaching, distance learning, e-learning, virtual classroom
Student engagement	participation, involvement, motivation
Engineering education	engineering students, STEM education

Many databases also use a controlled vocabulary (subject headings or a thesaurus, such as MeSH in medicine). Look up your concepts there, because indexers assign these terms consistently even when authors use different words.

Step 3: Choose your databases

Pick sources that fit your discipline, not just the ones you already know. A typical mix is one or two subject databases, one large multidisciplinary index and your library catalogue for books.

• Subject databases cover one field in depth, for example PubMed for medicine, ERIC for education, IEEE Xplore for engineering or PsycInfo for psychology.
• Multidisciplinary indexes such as Web of Science or Scopus help you find highly cited work and follow citations forwards and backwards. Access usually depends on your institution’s licence.
• Google Scholar is free and broad, good for a quick overview and for finding the full text of a known paper.
• Library catalogue and discovery service for monographs, edited volumes and theses.

Your university library’s subject guides list the databases your institution licenses. They are worth ten minutes of reading before you start.

Step 4: Combine terms into search strings

Use Boolean operators to connect your terms:

• OR within a concept: "remote teaching" OR "online teaching" OR "distance learning"
• AND between concepts: (remote teaching terms) AND (engagement terms) AND (engineering terms)
• NOT sparingly, because it can exclude relevant papers.
• Quotation marks for exact phrases and an asterisk for truncation, e.g. engag* finds engage, engagement and engaging. Syntax differs slightly between databases, so check the help page.

Then apply filters: publication years, language, document type and peer-reviewed status. Write down which filters you used and why.

Step 5: Screen in two passes

1. Read titles and abstracts and keep anything that might be relevant.
2. Read the full text of the remaining papers and decide against clear inclusion criteria, for example topic, method, population and time period.
3. Note for each excluded paper a short reason. For a systematic review this is mandatory; for a thesis it simply saves you from re-reading the same paper twice.

Step 6: Follow the citation trail

Once you have a few strong papers, use them as seeds. Check their reference lists (backward searching) and look up who has cited them since (forward searching) in Google Scholar, Scopus or Web of Science. This “snowballing” often finds key studies your keyword search missed. Some AI research tools can speed up this step, but treat their output as suggestions to verify.

Step 7: Save and document everything

Import every relevant hit into a reference manager as you go, with the PDF attached where you have access. Alongside it, keep a short search log:

• Date of each search
• Database and interface used
• Exact search string and filters
• Number of results and number kept
• Ideas for the next round

Note: some departments require a documented search strategy in the methods chapter, especially for systematic or scoping reviews. Check your module handbook or ask your supervisor early.

How you know you are done

You will rarely find “everything”. A practical signal is saturation: new searches and citation chasing keep returning papers you already have. At that point move on to reading, sorting and writing. The guide on writing a literature review explains how to turn your collection into an argument, and the literature section lists all related guides.

Common mistakes to avoid

• Searching only with the words from your title instead of the vocabulary of the field.
• Relying on the first page of Google Scholar.
• Downloading PDFs without saving the reference data, then rebuilding citations by hand later.
• Not recording search strings, so the search cannot be repeated or updated.
• Stopping after one round. The first search is mainly a lesson in terminology.