This funding provides enhancements to the UK Generations and Gender Survey (GGS). We will apply recently learned best practices in online survey methodology to our data collection effort. The survey will be transferred to the most appropriate software, which will enable improvements to the look and feel, reduce break-off and item missingness, and increase data quality. We will test the instrument on various devices, paying particular attention to smartphones, and redesign as necessary. The funding will also allow the development of online partnership and fertility histories, an area which has not been addressed in online survey methodology research.