A primary source serves as the original source of information about a given topic. Here a list of qualifying requirements: an interview, news footage of a live event, original data sets, original research, interviews, speeches, a diary, letters, a photograph, audio recordings, social media such as a tweet or a Facebook post, an autobiography, and the witnessing of an event or artifact, and original document that was created while an event was being researched can also qualify as a primary source.
Art has pictures
EWL has poems, literature, poems, creative fiction, fiction,
Natural Science has experiments that are written up in journals/data
Social Science has surveys, data, statistics, and first-hand events