We utilize online surveys as a comprehensive tool for collecting various digital data about people's attitudes, traits, and behaviors. This includes trace data from mobile apps, search queries, and website visits to, for example, draw conclusions about people’s living conditions. This is accompanied by research on smartphone sensors, such as accelerometer data for inferring motion conditions and activity levels. Similarly, we introduce qualitative research impulses to quantitative data collection. We started to work on fusing conversational AI-based interviewers with online surveys and gather voice answers to open narrative questions that are recorded through the built-in microphone of smartphones. In doing so, we are going beyond pure text-as-data methods extracting tonal cues to infer emotional and affective states in situ. Finally, we successively engage in social media sampling strategies evaluating data integrity. This especially includes the threat through bots that potentially shift research outcomes.
