Indicator Harmonization in Mobile Data Collection for Humanitarian and Development Monitoring: A Systematic Review of Methods, Governance Approaches, and Reported Outcomes

This systematic review synthesizes evidence on methods used to harmonize indicator definitions and variable structures across projects using mobile data collection platforms (ODK, CommCare, KoboToolbox, SurveyCTO, and similar tools) in humanitarian and development contexts. Mobile data collection platforms have become foundational infrastructure for monitoring and evaluation (M&E) in humanitarian and development settings. However, the lack of standardized indicator definitions and variable naming conventions across projects creates significant barriers to cross-project aggregation and alignment with global reporting frameworks such as the SDGs and humanitarian cluster standards. This review addresses a critical gap by systematically examining: (1) technical approaches to harmonization including naming conventions, data dictionaries, canonical variables, and metadata schemas; (2) governance mechanisms such as centralized standards, approval workflows, and version control; (3) platform-specific influences on harmonization strategies; (4) reported outcomes related to data quality, aggregation, and analytics readiness; and (5) challenges and limitations encountered in harmonization efforts. The review includes both peer-reviewed literature and grey literature (technical reports, implementation guides, NGO guidance documents) given the practice-driven nature of this topic. Findings will inform practitioners implementing data standardization initiatives and identify research gaps for the academic community.