A discussion I had recently made me realize that the concept of historical information hierarchy is not widely understood. My conversation partners seemed perturbed that I would suggest that using Findagrave.com as a sole source for an online collaborative tree profile is not a strong practice. They seemed rather more bothered when I said that there are usually stronger source types than a mere gravestone for coming to the most confident conclusions about death and burial facts. "How do you know that the information on your death certificate is correct?" one said. "The information on that could be wrong and the gravestone right!" I got the impression that this person was understanding things according to a my-source-vs.-your-source framework. By this perspective, who in the world am I to suggest that "my source" is "better" than this person's source? I tried to explain about primary vs. secondary sources for given facts, and about different gradations even within those categories. The person came back and said, "well, my secondary source could be right while your primary source could be wrong."
Yes, this is true. My primary source could be wrong and his secondary source could be right. But this is beside the point. Why? Because responsible, well-trained historians know to privilege sources created at the time of an event in question by people who were there to witness it. None other than Elizabeth Shown Mills duly notes this straightaway in her authoritative tome, Evidence Explained:
"Information is classed or weighed according to its origin. [Then she defines primary and secondary information.] As a rule, primary information carries more weight than secondary, although either class of informants can err." (ESM, Evidence Explained: Citing History Sources from Artifacts to Cyberspace, Third Edition Revised, Baltimore: Genealogical Publishing Company, 2015, pg. 25.)
"Ah, you see?" I hear you say, "EITHER class can err!" Absolutely. But when we're comparing one primary source and one secondary source, we have to give more weight to the primary source until we have more information. How do we start figuring out that the secondary source has correct information while the primary source has incorrect information, if it comes to that? Typically this is done with OTHER PRIMARY SOURCES rather than with other secondary sources....because (you guessed it) primary information has more clout as historical witness to its stated facts.
So, let's come back to our particular scenario. Which source should I privilege, in the absence of other sources, for death and burial information: a Findagrave.com memorial page or a death certificate? The answer is now clear. Provided it was obtained from a reputable repository (county clerk, archive, library, subscription service, etc.), the death certificate carries decidedly more weight. This is not to say that the one source is for sure correct while the other is for sure wrong. It merely means that the document is, on face, a weightier bit of evidence.
"But," you say, "what about the gravestone itself? Isn't that a primary source on par with the death certificate?" Actually, not in most cases. Why? Because unless we have direct paperwork telling us WHEN the gravestone was made, who made it, for whom it was made specifically, and when it was placed atop the gravesite, we have to put it in a bit more inferior of a source class than that of a death certificate if we're looking for the most authentic death and burial information. Remember, in most cases the death certificate will be made right at the time and place of death, and within just a few days of burial. Something similar may be true of a gravestone, but the stone itself will rarely supply you with much of this specific information. Again, the stone could be correct (in most cases it probably is), but without stronger primary sources accompanying it, we have to assign it a slightly lower amount of clout. A death certificate, even an obituary, are more to be sought-after for confident support of death and burial facts. (If the obituary and the death certificate disagree on a given fact, we have a trickier problem than if both of these documents agree with each other and disagree with the gravestone by itself. Again, we would need more primary source information, or some sophisticated triangulation by other means, for any resolution to this problem.)
"But what if there is no death certificate or obituary?" you ask. "What if my searching has only turned up a gravestone for a person's death/burial information?" Well, then your confidence for these facts must remain less strong than it would be if you had better sources. Is that a disappointing answer? Welcome to historical research! Ask any trained historian (who has had to make do with non-existent or next-to-impossible-to-find primary sources) how many lingering questions they have. As a genealogist, you're going to leave this world with many such questions, and many facts that you wish you could have supported better. You therefore admit this and chronicle it in detail in your notes. What you don't do is slap a Findagrave.com memorial citation on a death/burial fact and pretend that you have resolved the issue in just the same way as if you had stronger records at your disposal. The objective quality of evidence for a given fact isn't dependent upon the researcher's feelings and circumstances. There are only well supported assertions and less well supported assertions.
I love gravestones, and I love to go graving. I really do. I also think that gravestones are valuable historical evidence. I even like Findagrave.com (though I much prefer Billiongraves.com these days). It's a fun site; I get the appeal. But if you're serious about doing good research, you simply must use this tool far more carefully than many in the wider genealogical community seem prepared to do. Just because a source is more easily within your reach doesn't make it the best source you could find or use, and ESPECIALLY not the only one you should/could use. Always ask yourself the following questions: what is this source, who made it, when was it made, and how does it compare to other sources? The world of historical evidence is not democratic.