How to write the literature review of your research paper

Many researchers struggle when it comes to writing literature review for their research paper. A literature review is a comprehensive overview of all the knowledge available on a specific topic till date. When you decide on a research topic, usually the first step you take in the direction of conducting research is learn more about the previous research published on the topic, and this eventually translates into literature review when you write your research paper. Literature review is one of the pillars on which your research idea stands since it provides context, relevance, and background to the research problem you are exploring.  

Types of literature review

Literature reviews can be categorized as experimental and theoretical. Experimental literature review basically refers to surveying all the information available on a particular topic and critically analyzing the gaps that need to be worked upon. In this sense, it essentially forms the first experiment of any research project. The more extensive the review, the more precise and systematic the research project will be. Therefore, it is one of the most critical parts of one’s research.

Theoretical literature review essentially involves two steps: 

1. Surveying and critically reading the existing literature: this step is commonly referred to as experimental literature review.
2. Summarizing and actually penning down the gist of your review in an organized manner: this is known as theoretical review.

Literature review could be a part of a dissertation or research article and a stand-alone literature review. Let us look at this in more detail.

Literature reviews for dissertation/research article

Every research report/ thesis/research article begins with an introduction to the topic of research. This forms the literature review for the article. The main purpose of the review is to introduce the readers to the need for conducting the said research. A literature review should begin with a thorough literature search using the main keywords in relevant online databases such as Google Scholar, PubMed, etc. Once all the relevant literature has been gathered, it should be organized as follows:

1. Background literature about the broad research topic to introduce the readers to the field of study.
2. Recent progress on the study topic which can be organized thematically or chronologically. Ideally, separate themes should be discussed in a chronological manner to describe how research in the field has evolved over time and to highlight the progress in the field.
3. The review should include a comparison and contrast of different studies. Discussing the controversial aspects helps to identify the main gaps that need to be worked upon. This is essential for defining the problem statement of the study and highlighting the significance of the research under question.
4. Once a problem statement has been defined, the strengths and pitfalls of other studies that have tackled the problem statement should be discussed. This is important for outlining the need and novelty of the research.

A literature review should not be a mere recounting of all the available information. It should be a critical and analytical summary of the selected literature that guides the readers through the central theme of the research.

Stand-alone literature reviews

Literature reviews can also be written as stand-alone articles. These are not different from the literature review sections described above; however, they are not followed by experimental data.

They basically fall into 2 broad categories: narrative reviews and systematic reviews.

1. Narrative reviews

These are theoretical discussions of relevant information on a particular topic and its critical analysis. These are mostly qualitative in nature similar to the review sections of larger articles.

Narrative reviews are usually organized as follows:

Introduction that establishes the context of the field of research and the topic of the review

Body is normally used for describing the different themes under the main topic by dividing them into different subheadings. This section compares and contrasts published studies and identifies gaps that have not been addressed or have been unsuccessfully addressed.

Conclusions. This section differs slightly between reviews which are part of research articles and narrative reviews. The section describes the main conclusions from analysis of all the current studies and puts forth further avenues for research. This section requires critical interpretation by the author such that the review adds value to existing literature. It should bring out ideas/hypotheses that can explain any discrepancies and provide solutions to existing problems.

2. Systematic reviews

On the other hand, systematic reviews follow a well-planned methodology to qualitatively or quantitatively analyze a defined number of studies. They usually focus on a single question and have clear study objectives that are worked upon in a systematic manner. These studies are based on a well-defined strategy unlike narrative reviews. Systematic reviews and narrative reviews are organized slightly differently. The details are described below:

Introduction: Systematic reviews begin with specific research questions that are defined in terms of the samples and research outcomes to be studied.

Methods (only for systematic reviews):  These studies have a comprehensive methodology that starts by narrowing down the literature for the review. Usually, specific inclusion/exclusion criteria are set based on the research questions and databases are searched based on these criteria. Once the sample studies have been shortlisted, they are analyzed in detail.

Results: The results section for these studies involves comprehensive data analysis to determine the significance of the study outcomes. Systematic reviews can be accompanied with Meta-analysis which involves statistical analysis of the included studies to increase the power of the results.

Discussion: This section usually interprets the study data based on their weighted significance and the power of the results. The study therefore provides strengthened results that are validated by the scientific rigor of the analytical method.

Before starting to write a review, it is important to determine what kind of review you want to write and follow the appropriate style and guidelines. An effective literature review is important for the complete life cycle of a research from defining the right research goals to correctly interpreting and presenting the research results.

If you wish to learn in more depth how to conduct literature search, check out this course designed exclusively for researchers: How to conduct an effective literature search and review.