What Is a Scoping Review (PRISMA-ScR)? A Methodology Guide

Picture a doctoral candidate sitting in front of two decades of research on social-emotional learning in Pre-Kindergarten classrooms. The literature is sprawling. Some studies report on curricula. Others examine school-wide behavioral systems. Others focus on mindfulness, executive function training, or one-on-one teacher practices. The frameworks have different theoretical roots, target different age bands, and measure outcomes in radically different ways. Where do you even begin?

If the goal is to rank which intervention produces the largest effect on prosocial behavior, the right tool is a systematic review—or, where data allow, a meta-analysis. But if the goal is something different—surveying what exists, identifying what is missing, and clarifying where the field needs to go next—a scoping review is the methodology of choice. That distinction is precisely why Ranya Omran’s 2026 scoping review of Pre-Kindergarten behavioral and SEL frameworks adopted the PRISMA Extension for Scoping Reviews (PRISMA-ScR) as its guiding protocol [1].

This article explains what a scoping review actually does, how it differs from a systematic review, why PRISMA-ScR has become the field’s reporting standard, and how the methodology shaped what Omran’s review found—and, just as importantly, what it identified as absent from the literature.

What a Scoping Review Actually Does

A scoping review is a structured research method used to map the breadth, content, and conceptual boundaries of a literature on a given topic. Unlike a systematic review, which evaluates the quality of individual studies, a scoping review identifies what kinds of evidence exist and where structural gaps remain.

In the Omran review, this distinction is stated explicitly: the purpose was “not to assess the quality of individual studies — that is the work of a systematic review — but to map the landscape of what exists and what does not” [1]. That single sentence anchors every downstream methodological choice—from the breadth of study types accepted to the way findings were organized into a six-category taxonomy and a four-gap analysis.

The driving questions were correspondingly different from what a systematic review would ask. Rather than “Which Pre-K SEL curriculum is most effective?”, the review asked: What behavioral modification and social-emotional learning frameworks currently exist for children aged 3 to 5? What outcomes and measurement tools have been used? And what structural and methodological gaps would a new framework need to address? [1]

Scoping Review vs. Systematic Review: The Critical Distinction

This is where novice researchers most often get tripped up. The two methods look superficially similar—both are structured, both follow reporting protocols, both involve database searching and multi-stage screening—but they answer fundamentally different questions.

Different Purposes, Different Methods

A systematic review asks a narrow, effect-focused question: across high-quality studies of a defined intervention, what is the magnitude and direction of the outcome? It applies strict eligibility criteria, conducts formal quality appraisal, and—when data permit—pools effects statistically.

A scoping review asks a wider, descriptive question: what does the literature on this topic contain, and what is absent from it? It catalogs. It maps. It identifies where evidence clusters densely and where it thins to nothing. Crucially, it does not judge whether individual studies are methodologically strong or weak, because the goal is to characterize the landscape, not to rank its contents [1].

That methodological choice has direct downstream consequences. Because scoping reviews do not run quality appraisal, they can legitimately include heterogeneous study types within a single map—peer-reviewed journal articles, systematic reviews, meta-analyses, and government research reports, for example, all sat together inside the Omran review’s inclusion criteria [1]. That kind of breadth would be inappropriate for a systematic review, where comparability of study design is essential to producing a defensible effect estimate.

A Side-by-Side Comparison

The two methods diverge across nearly every dimension that matters to a researcher choosing between them:

Choosing the wrong method for the question on the table is one of the most common errors in early-career review work. A scoping design cannot tell you whether PATHS, Second Step, or PBIS works best—but a systematic design cannot tell you what kind of integrated framework no one has built yet [1].

Why PRISMA-ScR Matters

PRISMA-ScR—the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews—is the reporting standard developed by Tricco and colleagues in 2018 to bring methodological transparency to a method that, until then, had been applied inconsistently across disciplines [2].

The Reporting Standard

PRISMA-ScR is, at its core, a checklist. It specifies what authors must report at every stage of a scoping review: how research questions are framed, what databases are searched, which inclusion and exclusion criteria are applied, how studies are screened, and how findings are extracted and synthesized [2].

The Omran review states that the PRISMA-ScR checklist was “completed in full and is included as a supplementary document,” allowing other researchers to assess the methodology against the published standard [1].

This kind of transparency matters more than it first appears. Scoping reviews, by their nature, involve interpretive judgment—about which studies to include, how to group them into categories, and how to characterize the gaps. PRISMA-ScR does not eliminate that judgment, but it makes it traceable.

A reader can examine the search strings, the criteria, and the screening process and decide for themselves whether the review’s conclusions follow from the methodology applied [2].

Why Tricco et al.’s Framework Became the Standard

Scoping reviews had been described in the literature for nearly two decades before 2018, but the method lacked a unified reporting framework. PRISMA-ScR was developed through expert consensus to fill that gap [2]. Structurally, it draws from the original PRISMA statement for systematic reviews while adapting the items that do not apply to scoping work—most notably, removing mandatory quality appraisal [2].

For graduate students designing thesis-level reviews, or researchers preparing manuscripts for journals that have adopted reporting-standard requirements, PRISMA-ScR is now the default expectation. It gives scoping reviews the same kind of methodological legibility that systematic reviews have enjoyed for years.

How PRISMA-ScR Shaped the Omran Pre-K Scoping Review

The Omran review applied PRISMA-ScR to a specific question: what does the literature on Pre-Kindergarten behavioral modification and SEL frameworks for children aged 3 to 5 actually contain? [1]

Mapping a Landscape, Not Judging Studies

The choice of a scoping design—rather than a systematic review of any single program—was deliberate and consequential. The review’s inclusion criteria were intentionally broad: peer-reviewed journal articles, systematic reviews, meta-analyses, and government research reports across a 25-year window from 2000 through 2024, drawing on Google Scholar, ERIC, PsycINFO, and CINAHL [1].

Studies on individual teacher practices without a named framework were excluded, but methodological diversity across framework types was actively welcomed—because the point was to see the field whole, not to compare effect sizes within it.

That design enabled the review to ask a question a systematic review structurally cannot. A systematic review can compare PATHS to Second Step on a defined outcome. A scoping review can do something different and, in this case, strategically more important:

It can surface what kind of framework no one has built yet [1]. That capacity to identify absence—not just to measure presence—is what makes scoping reviews valuable when the most consequential question facing a field is “what is missing?”

What the Methodology Made Visible

Because the review was scoping in design, it could identify patterns no individual study would surface. Six framework categories emerged from the analysis—Universal SEL Curricula, School-Wide Behavioral Systems (primarily PBIS), Mindfulness-Based Interventions, Executive Function Training, Teacher-Mediated Co-Regulation, and Hybrid/Multi-Component Frameworks [1].

By then assessing all six against four operational requirements, the review identified four structural gaps that together describe what a new framework would need to provide [1] A20 — The Four Missing Pieces.

That kind of conceptual map—six categories, four gaps, one absent integrated framework—is precisely the deliverable a scoping review is designed to produce. A systematic review of any single program would have generated a narrower, and in this case less actionable, kind of insight.

A Note on Preprint Status

It is worth flagging that the Omran review is a preprint, and the search and screening phases are explicitly described as “in progress” at the time of publication [1]. Final inclusion counts, the PRISMA-ScR flow diagram (Figure 1), and complete descriptive statistics are marked in the manuscript as pending and slated to be added prior to journal submission [1].

The qualitative findings—the six categories, the measurement-accessibility critique, and the four-gap analysis—are presented based on the search currently underway and will be confirmed in the final version. That kind of staged transparency is part of what PRISMA-ScR reporting permits, and it is consistent with the preprint convention of releasing methodologically sound but data-evolving work for community review A27 — Limitations and Status.

When Researchers Should Choose a Scoping Review

For graduate students and early-career researchers trying to decide between review methods, a few practical criteria help clarify when scoping is the right choice:

• When the field is broad, fragmented, or still emerging. If multiple kinds of frameworks, methods, or theoretical traditions sit under the same conceptual umbrella, scoping helps make sense of the terrain before any meaningful effect comparison is feasible.
• When the goal is to identify gaps. Systematic reviews tell you whether something works. Scoping reviews tell you what has not been built or studied. For thesis groundwork or curriculum-development planning, that second answer is often the more useful one [1].
• When study heterogeneity makes pooled effect estimates inappropriate. If the literature spans curricula, school-wide systems, training programs, and one-on-one approaches, pooling effects would be statistically unsound. Mapping them is the more honest move.
• When informing curriculum design or policy, not clinical decision-making. Scoping reviews are well-suited to feed into program design, education policy briefs, and curriculum architecture, where understanding the structure of the field matters more than ranking interventions.

The Omran review fits each of these criteria neatly. The Pre-K behavioral and SEL field is broad and fragmented. The driving research question is centered on gaps. The included studies are heterogeneous by design. And the review is framed explicitly as preparatory groundwork for a forthcoming curriculum-development project [1].