Just-N Framework: Interactive Application

Just-N Framework: Interactive Application is a Shiny app that guides researchers from any discipline in deciding, applying, and justifying the most appropriate sample size strategy for their study, whether quantitative, qualitative, or mixed-methods. It runs entirely in the browser via Shinylive (WebAssembly): no server or R installation required.

▶️ Open app 📂 GitHub repository 🔗 DOI: 10.5281/zenodo.19860616

App contents

The application is organised into five tabs:

• Introduction: explains why justifying sample size is a central methodological decision, and provides an initial navigation guide.
• Quantitative: a parameterised decision tree leading to one of five strategies – SESOI/statistical power (a priori), estimation precision (confidence intervals), sequential/adaptive designs, prior evidence and comparability, and cost-benefit analysis – each with interactive calculators (pwr, Fisher-z) and, for SESOI, Monte Carlo simulations.
• Qualitative: a decision tree for five strategies (theoretical or data saturation, diversity and representativeness, community-based participatory research (CBPR), feasibility and ethical commitments, and narrative justification) with methodological guides and citable references per strategy.
• Mixed: guidance for designs combining quantitative and qualitative components.
• References: full bibliography (~88 sources) with APA metadata.

Complementary resource

This app is the interactive version of the static document Just-N Framework, which presents the same strategies in table format with linked references. Both resources are self-contained and can be used independently.

Cite

Leongómez, J. D. (2026). Just-N Framework: Interactive Application (v1.0). Zenodo. https://doi.org/10.5281/zenodo.19860616