Trade unions. Depending on your age and political leanings, these words might conjure up images of the Tolpuddle martyrs, Jarrow marchers, or flying pickets; staunch defenders of workers rights or dangerous reactionaries threatening the country's future economic growth.

The unions associated with school teachers, nurses, and miners certainly have the highest profiles, but a number of unions represent scientists, particularly scientists working in the public sector.

A few years ago I became a postdoc. Along with the information about orientation sessions for new members of staff and the Universities Superannuation Scheme that appeared in my post over the first few days, I was surprised to find an invitation to join the Association of University Teachers (AUT). I'd never considered that scientists could join unions, and I realised that I didn't really know much about what unions did, beyond the lurid newspaper headlines. I was in a quandry. Suddenly I was earning a real salary for the first time, and now these people were asking me to shell out some of my hard-earned cash every month. But for what?

My experiment with being a postdoc didn't last long, and I never did make a decision about whether to join the union (except, I guess, by default). But if you're a new contract researcher or are paid for teaching part-time at a university (even if you're still a postgrad student), perhaps you ought to be better informed about what unions do, or don't, have to offer.

This week, we hear two views on union membership, so before you jump in, or write the issue off as irrelevant, see what our contributors have to say.

"You may not want to get actively involved, but think of it as insurance. Your union can help if you want better pay or if anything bad happens to you, but like any insurance it can only help if you have been a member for some time prior to a crisis, " say members of the AUT's Contract Research Staff Committee.

"I firmly believe that everyone should be a member of an appropriate trade union. Unfortunately though, I don't think there is, at the moment, a union for contract research staff, " laments Stephen Clark, long-term contract researcher.

If you have questions about union membership or experiences to share, why not join our Forum to discuss union membership further?