Hi Tiana, welcome aboard. I assume you're asking about the scenario where you are attempting to create a new profile, and you're being asked to look at a bunch of other profiles with the same or very similar names to see if that person is already here. If the potential match has an active profile manager, you should collaborate with him or her and compare notes. But otherwise, IMHO, if you see an unconnected profile where most of the data fits, and it's open and available, I would say it's OK go ahead and claim it. Here's why: There was a time (maybe it's still in effect!) when some members felt that in order to create a single worldwide tree, it would be a good idea to create a profile for everybody who ever existed (for example, by walking through a cemetery and taking names and dates from tombstones, but not doing any further research). The expectation was that eventually someone such as you would come along, find that person to be one of your ancestors, and beef up that profile. If that seems like a realistic possibility for what you're evaluating, I say go for it. The alternative is say it's not a match and go ahead and create a new profile. If you do that, someone else could very well come along eventually and propose a merge with the one you were considering, so you would get to evaluate it again. Really, there's no harm done either way.
That's just the opinion of an old-timer who has been here here for a while, not an authoritative answer. Others may disagree, and are welcome to chime in.
