Narrative Literature Reviews

1. Define the topic and review question.
2. Identify search terms related to the different concepts that make up the topic.
3. Select the information sources and search strategies to be applied.
4. Collect the sources resulting from the research.
5. Extract the data and organize it according to the logical structure you want to give to the review.
6. Write the review.

Before defining the review question, it is recommended to conduct preliminary research on the topic. This step allows for a general characterization of the subject, which facilitates the refinement of the question—either making it more focused or more comprehensive, as necessary.

With the question already outlined, the next step is to identify the main concepts that comprise it. For each concept, a list of relevant terms should be drawn up, including synonyms, linguistic variations, related terms, and, where applicable, controlled vocabulary. This selection should be based on both prior knowledge of the topic and the exploratory research carried out previously, and should consider the translation of terms into English, as this is the main indexing language of the reference databases.

Publishing practices vary across fields of knowledge, which directly influences the types of sources to consider in a bibliographic search. Depending on the discipline, the following may be relevant:

• Books;
• Scientific articles published in specialized journals;
• Gray literature, such as conference papers, theses and dissertations, technical or institutional reports, and standards/guidelines.

Locating these resources requires careful research in different types of sources, such as library catalogs, institutional repositories, scientific databases, and websites of recognized organizations or institutions in the field. Universidade Católica Portuguesa provides access to EBSCO Discovery Service, an aggregator interface that allows integrated searching across all resources subscribed to by the institution, including the library's physical collection and other complementary sources.

For effective bibliographic research, it is essential to cross-reference different types of sources. Therefore, it is recommended to consult databases specific to your area of knowledge, as well as multidisciplinary resources such as Scopus and Web of Science. These platforms offer advanced tools for analyzing results, which can assist in defining selection criteria and identifying the most relevant publications.

In addition, artificial intelligence-based tools have emerged that can play an increasingly important role in the formulation of research strategies. One example is Scopus AI, which allows users to perform searches in natural language, retrieve thematic summaries, and explore authors, topics, and related issues quickly and intuitively.

Boolean Search in Databases and Repositories

The traditional way of searching scientific databases is based on the use of keywords combined with Boolean operators (AND, OR, NOT). These operators function as logical connectors that define the relationship between search terms. For example, when searching for anxiety AND adolescents, the database will only retrieve documents that contain both terms. The combination Anxiety OR adolescents will retrieve documents containing at least one of the two terms, and anxiety NOT adolescents will exclude those that mention “depression”.

In addition to combining terms, it is essential to define the search fields, i.e., where the terms should be searched. The most common fields include title, abstract, keywords, or combinations between them. For example, you can restrict the search so that a term appears only in the title, increasing the relevance of the results.

Other important features for refining your search include:

  - Quotation marks (“ ”): to search for exact phrases. For example, “anxiety disorder” ensures that the results contain exactly that phrase.

  - Truncation (*): to retrieve variations of a word. For example, psycholog* will retrieve psychology, psychologist, among others.

  - Parentheses (): to group terms and operators, especially in more complex searches. Example: (anxiety OR stress) AND teen*.

Snowball Search

In addition to database searches, one of the most effective strategies for identifying relevant sources is to start with documents that have already been selected as relevant. This process can be carried out in two main ways:

  - Manual search of the bibliographic references of the identified documents (backward citation searching). For example, when consulting a relevant article, one can explore the studies that this article cites, which allows one to go back in the line of research and identify foundational or contextual works.

  - Manual search in documents that cite the identified article (forward citation searching). This approach allows you to advance your line of research by identifying more recent studies that have used or are based on the article in question. Reference databases such as Scopus and Web of Science facilitate this type of search, as they provide direct links to articles that cite a particular source.

Natural Language Search

Advances in artificial intelligence have made significant contributions to the field of bibliographic research. Currently, several scientific databases integrate features that allow searches to be performed in natural language, i.e., using phrases instead of Boolean expressions. For example, instead of searching for anxiety AND adolescence, it is possible to write directly: “What are the effects of anxiety on adolescents?” and obtain relevant results.

One tool that exemplifies this evolution is Scopus AI, which allows users to explore research topics through natural language queries, suggesting related terms, refining the search, and facilitating the discovery of relevant scientific literature. Other resources, such as EBSCO Discovery Service and Web of Science, have also been incorporating similar features.

For effective management of the sources selected during the research, it is recommended to use bibliographic reference managers, such as Zotero or Mendeley. These tools allow, on the one hand, to organize sources in a structured way, facilitating access and subsequent reuse, and, on the other hand, to automate the process of creating citations and bibliographic references.

Articles

Cronin, P., Ryan, F., & Coughlan, M. (2008). Undertaking a literature review: a step-by-step approach. British Journal of Nursing, 17(1), 38–43. https://doi.org/10.12968/bjon.2008.17.1.28059

Ferrari, R. (2015). Writing narrative style literature reviews. Medical Writing, 24(4), 230–235. https://doi.org/10.1179/2047480615Z.000000000329

Grant, M. J., & Booth, A. (2009). A typology of reviews: an analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26(2), 91–108. https://doi.org/10.1111/j.1471-1842.2009.00848.x

Gregory, A. T., & Denniss, A. R. (2018). An Introduction to Writing Narrative and Systematic Reviews — Tasks, Tips and Traps for Aspiring Authors. Heart, Lung and Circulation, 27(7), 893–898. https://doi.org/10.1016/j.hlc.2018.03.027

Books

Aveyard, H., Payne, S., & Preston, N. (2021). A post-graduate’s guide to doing a literature review in health and social care (2n ed.). Mc Graw Hill, Open University Press.

Hart, C. (2025). Doing a literature review: releasing the research imagination (3rd ed.). Sage.

Ridley, D. (2012). The literature review: a step-by-step guide for students (2n ed.). SAGE.