This edited volume examines the challenges and innovations in collecting, measuring, and analysing data on sexual and gender minorities. As interest in sexual and gender minority research grows across academia and policy, the need for high-quality, inclusive, and comparable data has become increasingly urgent. However, existing data sources remain fragmented and methodologically complex.

The book provides a critical overview of major data sources, including general population surveys and dedicated LGBTIQ+ studies, assessing their strengths and limitations in terms of representativeness, comparability, and data quality. Drawing on the Total Survey Error framework, the book evaluates different approaches to measuring sexual orientation and gender identity. It offers practical guidance on questionnaire design and survey implementation to improve validity and inclusivity of survey measures. It also presents sampling approaches and post-survey adjustments for LGBTIQ+ studies.

Key Features:

• Provides a Total Survey Error framework for survey research focussing on sexual and gender minorities
• Provides an overview of data sources for LGBTIQ+ research, including international surveys and targeted studies
• Offers practical guidance on measuring sexual orientation and gender identity using state-of-the-art frameworks
• Discusses methodological challenges such as non-probability sampling, disclosure, and sampling hard-to-reach populations
• Highlights innovative approaches, including boost samples, online data collection, and census developments
• Includes cross-national perspectives and real-world case studies

The book aims to position survey research focussing on sexual and gender minorities as a rapidly evolving field and provides guidance for researchers, statisticians, data producers, and policy makers working on equality, diversity, and inclusion.

Dr Katharina Meitinger is a cross-cultural survey methodologist in the Department of Methodology and Statistics, Utrecht University. In her research she combines quantitative and qualitative approaches to enhance the inclusiveness, comparability, and quality of international survey data. Her work particularly focusses on measurement aspects of survey data. Her work on optimal cross-national survey measures for sexual and gender minorities is funded by the Dutch Research Council (NWO) via the projects 'Holding the rainbow up: Cross-cultural measurement of gender identification and sexual orientation (SOGI)' and 'Regional validity of survey questions on attitudes towards homosexuality in Europe: Combining web probing with small area estimation' (in collaboration with Angelo Moretti).

Dr Angelo Moretti is a survey statistician and works at Utrecht University in the Department of Methodology and Statistics. He is an elected member of the International Statistical Institute (ISI). He is part of the European Survey Research Association (ESRA) board, where he is currently serving as Conference Chair. He is the Principal Investigator of the 5-year ERC funded project ‘Small Area Estimation Methods to Monitor the Progress towards the Sustainable Development Goals at the Subnational Level in the European Union' (SAESDGs-EU). He has conducted research in small area estimation under multivariate mixed-models, survey calibration, mean squared error estimation based on bootstrap approaches, data integration methods (statistical matching and probabilistic record linkage), and weighting of non-probability samples. His work has been published in leading journals such as the Journal of the Royal Statistical Society: Series C, International Statistical Review, and the Journal of Survey Statistics and Methodology.