Ask HN: How to contribute to an academic field without Masters/PhD?

Contribute to academic os software, find academic who needs tech support, do the grunt work in preparing a dataset.

What about fields such as history or anthropology?

History: OCR of documents; image recognition for symbols; automatic translation;

Anthropology: language research; voice recognition of interviews; face recognition;

Highly depends on the topic and the project.

Conferences I think would be a great starting place. They allow you to find what is interesting to you and people with the same interests.

Work with a co-author.