What do you mean it shows up as an abstract. If you mean you go to pubmed and search for it, it shows up with only the abstract available, that could mean that its a published paper, but in order to get anything other than the abstract, you need to pay for it. Or, it could mean that he presented the data you guys collected in a poster or in a talk at a conference which has its own "journal" which it publishes the abstracts of the topics presented at its conferences...If this is the case, then it hasnt technically been published yet..only presented.
If its a published abstract I would mention it...they dont hold a whole lot of weight because there isnt really any peer review which they have to pass in order to be presented, but it shows you were involved in some research and since its just a poster, you dont have to have a whole lot of information which goes with it...for instance, I did a poster on a preliminary study that took me a month to put together for my masters project..
If it was a paper, I would only mention it if you understand it enough to explain the basics of what it was about. You dont necessarily need to know the nitty gritty, but atleast be able to show you have an decent understanding of the main principles behind the study. If you cant do that, then dont put it because I can see it causing some trouble during interviews.
