What to do when you have obtained very similar results with two different groups and you want to publish them both I started a collaboration with some other research group, where the main objective was to model some data. The project was very interesting to me, since I had obtained that data. After some months I got no news from them, I wrote them and they always told me they were very busy and had no time. I understood they were not interested anymore, so that I contacted another research group for the same collaboration objective, and this time, the collaboration progressed quickly, and we reached the stage where we are writing the paper about the modeling of the results. At this same point I got news from the other group, telling me they had obtained very interesting results with their modeling technique, and regretting the previous lack of contact. It turns out they have obtained much better modeling results than the "second" group. My problem is that I do not know what to do now. One option would be to publish two papers, one with each group, that would be very similar. Other option would be to decide for one of the two groups and go ahead, forgetting the other, but that would not be ethical. Perhaps a last option would be to publish both papers, bur giving them very different focus and audience.

What would you do here?
I'm surprised you did not mention the option that I would probably do: combine all data into one paper. Based on your description it sounds as if both data support a similar hypothesis/line of enquiry. If that is the case, publish one much stronger paper using two independent sets of data. All authors would need to be included. You could check with both teams to see if they agree. Speaking of which, have you asked them what they want to do?