The SOEP Innovation Sample (SOEP-IS) is a mixed-mode household panel survey data collection infrastructure established in 2011. It was designed to enable innovative data collection for the research community and is particularly well suited to establishing new and target-group-specific measurement instruments in long-term surveys, to conducting short-and long-term experiments, and to collecting non-survey data (such as biomarkers). Past SOEP-IS modules include economic behavioral experiments, implicit association tests (IAT), and complex procedures for measuring time use with day reconstruction method (DRM).

At its core, SOEP-IS collects survey data from approximately 4,500 individuals nested within 2,500 households. Approximately 25% of the SOEP-IS sample can be used for data collection projects which require interviewer assistance (CAPI mode), for example for collecting biomarker data. The remaining 75% of the sample can be used for extensive experimentation in the online data collection mode (CAWI), for example for vignette surveys and studies with add-on features (e.g. apps and diary studies). To maximize the inferential properties of a study, the online and offline samples can also be combined. This is particularly useful for drawing inferences to the general population in Germany. Usually, studies get assigned a subset of the SOEP-IS sample which fits their research purpose (e.g. 1,000 online respondents).

SOEP-IS offers two submission pathways: standard applications and collaborative grant-based applications. The standard application procedure is open to researchers from all scientific disciplines who wish to propose new survey modules for inclusion in SOEP-IS. The collaborative grant-based application pathway is intended for researchers who plan to include a SOEP-IS module in a third-party grant proposal (for example, to the DFG or ERC) and who coordinate this with SOEP.

While both pathways follow the same principles of transparency, peer review, and scientific quality, each has its own allocation within the annual SOEP-IS data-collection schedule. Modules submitted via the grant-based pathway cannot displace or reduce the time reserved for standard applications. This ensures balanced use of survey resources and equal access for all researchers.
Grant-based applications must cover the data-collection costs, since they generate additional administrative and financial expenses that cannot be covered by SOEP-IS core funding.

The GESIS Panel Infrastructure (GPI, see also Figure 1) encompasses the well-established GESIS Panel Population Sample (Gesis Panel.pop) and the new GESIS Panel Digital Behavioral Data Sample (GESIS Panel.dbd) that will be fully operational in Q2 of 2024. The quarterly fielded GESIS Panel Population Sample is a self-administered probability-based mixed-mode (CAWI and PAPI) panel of the German-speaking adult population permanently residing in Germany with a total sample size of about 5,000 respondents. Established in 2013, it is open to the academic public for primary and secondary research. While about 75% of all respondents participate online, the remaining quarter of our panelists participate in the mail mode (about 1,400 respondents), which we deem important since not everyone in Germany has access to the Internet, the skills to use it, or does want to participate online. The GESIS Panel.pop pursues a unified mixed-mode design with a mobile-first approach to reduce mode measurement effects. Due to the limitations of the mail mode, we only allow a maximum of four experimental groups per wave. The GESIS Panel.pop allows the submission of cross-sectional as well as longitudinal studies. It is especially suited for drawing inferences about the general population. 

In 2022, GESIS expanded its data collection capabilities by setting up a new data collection infrastructure – the GESIS Panel.dbd – for collecting digital behavioral data (DBD) on the adult German-speaking population that can be linked with survey data. The new infrastructure is expected to be fully operational in Q2 of 2024. Initially, the GESIS Panel.dbd will focus on recording study participants' web browsing behavior ("web tracking"). For this purpose, GESIS maintains and uses a web browser plugin (WebTrack) that records desktop/laptop browser usage at the level of individual website visits. Integrating web tracking data with longitudinal survey data can be considered the gold standard in investigating and explaining online media use and information-seeking behaviors and their effects. Respondents for the GESIS Panel.dbd will be recruited from non-probabilistic online-based sources, e.g., via advertisements on Facebook and Instagram, but also from high-quality survey programs such as ALLBUS or the GESIS Panel.pop. We aim to recruit approximately 1,000 participants to join the web tracking data collection. Although the GESIS Panel.dbd cannot be used to draw inferences about the general population, it allows for sophisticated experiments and innovative collections of web-tracking data.

NEPS next is the continuation of the long-running starting cohorts of the National Educational Panel Study (NEPS) in a wide-meshed surveying design with a mixed-mode survey (NEPS cohort design). The primary objective of NEPS next is to enhance understanding of the long-term effects of education on individuals’ lives. The study examines changes and continuities since the last survey, with a particular focus on (formal) educational outcomes (e.g., attainment/highest certificates), returns on the labor market (e.g., occupation, job characteristics, income, poverty) or non-monetary returns (e.g., satisfaction, health other noncognitive or socioemotional outcome measures) as well as social, political and cultural participation including background Information (household, family, children, place of residence). In combination with the rich NEPS data collected before wide-meshed surveying started, additional data from NEPS next enable further research into the long-term impacts and effects of education across the lifespan.

Participants from starting cohorts 1-5 as well as participants of starting cohort 6 older than 70 years are all invited to participate in NEPS next. Participants in NEPS next are contacted approximately every five years. The surveys are relatively short in duration and are conducted online or by telephone. The Leibniz Institute for Educational Trajectories (LIfBi) in Bamberg manages and maintains participants’ address and contact data with strict adherence to data protection standards.

The 2025 Call for Add-On Proposals for NEPS next (announced in November 2025) included a forward-looking reference to this Call for Proposals for the second funding phase of the SPP 2431. Please be aware that, due to restrictions in study planning schedules, the application window for the NEPS next Call for Add-On Proposals closed in January 2026. Consequently, only projects proposals submitted during that application window can be considered for add-on studies within NEPS next. All applicants whose proposals are being considered have already been contacted.

Two types of add-on projects that were possible:

1. Add-On Model 1 – Inclusion of additional questions (encompassing up to 2 minutes) in the outcome questionnaire
2. Add-On Model 2 – Invitation of NEPS next participants to an separate quantitative or qualitative study