When researchers design a literature review, one of the most frequent points of confusion is the nature of the inquiry. Is a scoping review qualitative or quantitative? The direct answer is that a scoping review is neither exclusively qualitative nor quantitative; it is a methodological framework designed to map and summarize existing evidence, regardless of the study designs included. This approach is particularly useful when a research topic is broad, emerging, or underexplored, as it allows for a comprehensive overview of the size, scope, and nature of available literature.
Understanding the Scoping Review Methodology
A scoping review follows a systematic methodology, but its primary goal differs significantly from that of a systematic review. While systematic reviews often seek to answer a specific research question through a quantitative synthesis (meta-analysis) or a deep qualitative integration, scoping reviews aim to "map" the landscape of available literature. The process involves identifying, reviewing, and collating key evidence to understand how a research field is structured, what concepts or themes have been explored, and what gaps exist. This makes the methodology inherently flexible, accommodating various types of primary studies without prioritizing one specific epistemological stance.
Mixed Methods as a Core Feature
The question of whether a scoping review is qualitative or quantitative is often clarified by looking at its inclusion criteria. A robust scoping review will frequently include quantitative studies, such as randomized controlled trials or epidemiological surveys, to capture statistical prevalence and outcomes. Simultaneously, it will equally incorporate qualitative research, such as phenomenological interviews or grounded theory, to capture nuanced experiences and contextual insights. This intentional integration allows the review to present a holistic picture of the evidence, bridging numerical data with human interpretation.
Distinguishing from Systematic Reviews Focus on Quantification vs. Exploration The primary distinction between a scoping review and a traditional systematic review lies in the analytical depth. A systematic review typically requires a quantitative synthesis, using statistical methods to aggregate data from multiple studies to calculate an effect size. In contrast, a scoping review usually stops at the stage of charting the data. It involves categorizing evidence into themes or frameworks rather than statistically pooling results. Therefore, while a systematic review might determine *if* a treatment works, a scoping review is better suited to answer *what* interventions exist or *how* research is being conducted in a complex area. The Role of Study Design in Scoping
Focus on Quantification vs. Exploration
The primary distinction between a scoping review and a traditional systematic review lies in the analytical depth. A systematic review typically requires a quantitative synthesis, using statistical methods to aggregate data from multiple studies to calculate an effect size. In contrast, a scoping review usually stops at the stage of charting the data. It involves categorizing evidence into themes or frameworks rather than statistically pooling results. Therefore, while a systematic review might determine *if* a treatment works, a scoping review is better suited to answer *what* interventions exist or *how* research is being conducted in a complex area.
Because a scoping review can include mixed methods, the "quality" of the evidence is assessed on its relevance to the mapping exercise rather than its adherence to a single qualitative or quantitative quality rubric. Researchers utilizing this method accept that the strength of the evidence varies; a scoping review might include low-risk-of-bias trials alongside descriptive qualitative studies. The validity of the review depends on the transparency of the search strategy and the coherence of the thematic analysis used to organize the diverse studies, rather than on the aggregation of numerical data alone.
When to Choose This Approach
Researchers often turn to scoping reviews when they are entering a field that is not well-defined or when dealing with complex interventions that have not been uniformly studied. If the goal is to determine the feasibility of conducting a full systematic review with meta-analysis, a scoping review serves as the necessary preliminary step. It helps clarify the key concepts, terminology, and the gaps in the literature, ensuring that subsequent quantitative or qualitative work is grounded in a solid understanding of what is already known.
Conclusion on Methodological Classification
Ultimately, classifying a scoping review as strictly qualitative or quantitative misunderstands its purpose. It is a synthesis tool that prioritizes breadth of understanding over depth of causation. By design, it is an umbrella methodology that embraces the full spectrum of evidence, allowing researchers to visualize the contours of a research field. This flexibility ensures that the output is a comprehensive map, guiding future primary research regardless of the specific paradigms from which the included studies originated.
