The European Social Survey (ESS) is the largest European Research Infrastructure in the social sciences. Historically, the survey has been carried out every two years in about 30 countries using face-to-face interviewing. The ESS is moving to self-completion (combination of web and paper) as the interview mode. In 2023-2024 I did consulting work for the ESS, and since 2025 I am a member of the Core Scientific Team, being responsible for work around the mixed-mode transition. In particular I focus on the analysis of mode nonresponse and mode measurement effects, and will produce training and guidance for ESS users on how to use the mixed-mode data in practice.
Provenance and data quality are essential for supporting the reuse of data, especially when various data sources are combined in complex and iterative ways. Data linkage can be done at the level of people, space and time, and combinations of these dimensions. This task develops a framework for assessing the quality of linked data, proposes which of the quality indicators to use in metadata so that users understand the quality of data before linkage, and develops these indicators for both linkage across people, space and time (events) depending on the dataset. It concentrates on the linkage of datasets, not on linked data in the sense of the semantic web. In the project Social Science and Humanities Open Cloud-NL (SSHOC_NL) the large-scale infrastructures ODISSEI and CLARIAH together seek to provide a step-change for the social science and humanities.