Authorship as a topic has come up several times in my life recently. I wanted to share some helpful links (thanks Catherine Scott for finding them for me months ago) and hopefully helpful thoughts/summaries on what is expected from someone who appears as an author on a peer-reviewed scientific paper.
Background (helpful links):
As a quick summary, most people view research as coming in very roughly delineated steps or phases. In the beginning you start with (1) creating a research framework which needs to (2) get funding. Once there is funding, (3) specific, testable research questions need to be asked and experiments designed, then (4) data is collected. Once the data is in, it gets (5) analysed then (6) interpreted/discussed to make a sensible story that is then (7) written up for submission to a peer-reviewed journal with (8) help from colleagues to edit and revise. After it goes through peer-review, there will be (9) changes and edits (arguably, this should be part of (7)).
Many people I know feel that involvement in only ONE of the above (except perhaps 7) is NOT enough for authorship. For example, even though my graduate supervisor got funding for some of the materials that we used, many of the papers that I am currently working toward publishing this year will not include his name as an author. For another example, the undergraduate that did a co-op term to help me collect data for the largest part of my thesis will also not be an author on those papers, even though she helped me collect data 5 days a week for ~3 months. Both these people will, of course, feature VERY prominently in the Acknowledgments section of any papers they helped with but aren’t authors on.
That said, authorship is a very tricky topic in science. The above are just unofficial guidelines that I’ve seen from experience, reading (eg links above), and discussions with colleagues. Ultimately, the decision of who is included as an author on a paper requires discussion and agreement between the people involved, and that is all. There is no regulation or policing, and there are lots of completely reasonable exceptions to the rule.
I hope that was helpful. =]