What data does a robot learning project need, and how is it obtained? A student's survey on data collection and evaluation

A student is seeking experience from practitioners of robot learning projects: what their recent project tasks were, and whether training and testing require human videos, robot demonstrations with action recordings, or sensor data. What camera viewpoints, synchronized recording, annotations, or file formats the data needs to include; whether existing datasets are sufficient or self-collection is necessary; and how to work around insufficient data.