I recently did some voluntary work for a large NGO, and I would like to add this to both my CV and LinkedIn profile. The issue is that I have no idea what an appropriate job title might be. They asked for statistics advice on a manuscript/grey paper they are working on, so I've tentatively called this a "statistical consultant" role. I'm torn between thinking this is self-aggrandising, but also the best literal description.
A note: I have sent away this question to the person who requested the advice, with no response yet. I will update if I get one.
Edit: More detail on the work itself, as requested: I was sent two manuscripts, a costing analysis, and a very large dataset of a three year project. I was asked to give my opinion on the validity of the study design and statistical analysis, to read and comment on the manuscripts, and to explore the dataset for other potentially interesting questions and associations. I was fairly thorough and ended up writing around 800 words in comments and suggestions.
I also made suggestions for potential further research and wrote two Stata '.do' files to support these suggestions. I would estimate the work took around 40 hours, conducted in my spare time over the course of a couple of weeks.
Perhaps this particular context matters, too; this was initially intended to be a placement where I would work in-person at a research centre, but this was interrupted by COVID-19. I have also agreed to participate in continuing projects using the same data remotely until it becomes feasible I can undertake a full-time placement in the future.