It may not provide absolutely certain answers, but in my case it showed an almost certain connection that revealed an answer I had been searching for almost 10 years, and would have had difficulty finding, let alone being confident of, using paper alone. This is often the case where there have ben undocumented adoptions, irregular parentage or deliberate name changes (this latter being my case). For me, DNA was the answer, though of course I had to have the documented information as well.