This has consistently confused me. Let's say we've come up with a new algorithm to solve an existing problem. The algorithm itself isn't the contribution, apparently, so what is? The new way of solving the problem, whose *implementation* is given by the algorithm? Can anyone give me some examples of what is and is not a contribution?

MIKE

It may vary by field, but this is a link to guidelines for medical journals. One journal Ive submitted to you have to state what each author has done to meet the criteria.

Sorry if that's not what you meant though. I'm not sure what 'contribution' means. Would this be someone who has contributed something but does not qualify for full authorship, but would be listed in the acknowledgements?

Hm, that wasn't quite what I meant (but it was interesting nonetheless :-) ). What I meant more so was: if I'm trying to tell the reviewer the reason that my paper is useful, I need to provide a clear description of my contribution to the state of the art. But I've always had trouble distinguishing between the technical implementation (which isn't a "contribution", apparently) and the more generally applicable results. Does that make sense?