Methodological Pluralism in the Social Sciences: Integrating Quantitative and Qualitative Research for Robust Evidence

Abstract

Methodological pluralism is increasingly recognized as a defensible response to the complexity of social life, yet the use of quantitative and qualitative methods does not automatically produce stronger evidence. The decisive issue is integration: whether different forms of inquiry are connected through a clear logic that yields conclusions unavailable from either component alone. This conceptual review explains how purposeful quantitative-qualitative integration can improve the credibility, explanatory depth, contextual validity and practical usefulness of social-science research. It synthesizes contemporary mixed-methods scholarship with African and Nigerian work on indigenous methodologies, knowledge production, research capacity and evidence-informed policymaking. The paper distinguishes methodological pluralism from multimethod research, mixed methods and triangulation; examines pragmatist, critical realist, dialectical, transformative and indigenous foundations; and analyses integration across problem formulation, sampling, data collection, analysis and interpretation. Particular attention is given to African settings, where imported concepts, linguistic diversity, weak research-policy linkages, uneven methodological training and marginalization of local knowledge complicate the production of useful evidence. An Integrated Evidence Robustness Framework is developed around five connected stages: problem complexity, methodological differentiation, purposeful integration, integrative reasoning and warranted meta-inference. Six propositions specify the conditions under which plural designs are likely to strengthen evidence. The review concludes that methodological pluralism is best understood as disciplined openness rather than unrestricted eclecticism. Strong plural research protects the quality of each component, makes integration visible, treats divergence as evidence, and locates claims within their social, historical and institutional contexts. For African and Nigerian social science, this approach can support locally grounded theory, culturally credible measurement and more actionable links between research and public decision-making.