A few years back, during my graduate school years I participated in a regional project which brought together individuals from both industry and academia to carry out an engineering study to assess the vulnerability of the region in question to natural hazards like hurricanes. My participation lasted for about a year, was on a voluntary basis and was a great opportunity to learn new skills and get exposure to the local engineering community. I compiled a report at the end to document my findings and convinced one of the involved faculty members to sign it off as my official Master's thesis, which she did gladly due to the good quality of the work.
Years later, I still list this as work experience on my Resume/CV because the skills I learned and the work I did there remain relevant today. I had no official job title, but early on listed my job title as "Student Volunteer" or "Research Volunteer". However, I have noticed that as time went on I begin to list it under "Research Assistant", making it seem like the position was full-time and that I was "employed" under the nonprofit entity which was sponsoring the project, neither of which is true.
I'm on the hunt for jobs again and have been polishing up my CV, but this does begin to feel quite dishonest. The job was not full time, and I was not officially employed under this nonprofit organization. Everyone was pleased with my work but I'm not sure if this gives me license to make things look more rosy than they really are. Furthermore I've been told that in the country I live it is customary to slightly contort job titles to make them match individual job application, but from "Student Volunteer" all the way to "Research Assistant" seems like a bit of a stretch. Finally, I'm listing it under "Employment History" or "Work Experience", but neither was it a formal job, nor was I paid for it.
I definitely want to continue listing this in my Resume, but how do I do it in such a way that it's A) not dishonest and B) does not minimize the very high quality of work and degree of professionalism that I displayed?
Thanks!