Academia Stack Exchange is a question and answer site for academics and those enrolled in higher education. It only takes a minute to sign up.
Sign up to join this community
A group of researchers work in a problem that no one else works on, hence these researchers are cited only by themselves. They cite other papers, too.
How does the academia consider these cases?
Important update:
From the answers received, I noticed that I have wrongly formulated the question. I don't care if that group of researchers cite other papers. My concern is what if they are cited only by themselves.
One can see this from a philosophical perspective ("If a tree falls in the forest and nobody hears it, did it fall?") and one can also approach this from a perspective of "All research is useful, it may just not be useful right now (as @Buffy has in their answer).
But the reality is that if nobody cares about a certain research direction, then that is a statement about the work as well: It is, truly, irrelevant for all practical purposes. Of course, it is possible that at some point in the future someone might start to care, but the likelihood of that happening is rather small even if I am sure that we can come up with examples.
In many parts of academia, one measures the influence of researchers by their number of citations. It is certainly debatable whether that is an accurate metric, but it is a useful metric for sure and if someone's work does not receive any outside citations, that is a meaningful statement as well.
It is not unusual for some researchers to receive few or no outside citations, but it would be strange for a researcher or research team to give no outside citations. That is because it is always possible to place one's own work in some academic context based on existing published literature. To not give any citations outside one's own group would suggest that the group is not very good at doing a good literature review of their topic area (and it would probably lead their papers to get rejected from journals, so it is unlikely to show up in published literature).
The remainder of my answer pertains to the more common case where a researcher receives no outside citations. One would ideally wish that the relevance of an academic paper is determined purely by the topic, substance and quality of the work. However, as a practical matter, literature that has fewer citations (particularly fewer external citations) is harder to find/notice when searching for papers, and literature that only has self-citations does not show up in outside papers by other authors in the literature review. This makes it less likely you will find the paper with a search engine, or using a "track-back" search where you start from existing known papers and then expand out via the citations. Consequently, certain papers can get caught in the academic equivalent of a black-hole.
There is of course nothing inherently wrong with self-citations, and they are a natural part of what happens when researchers write multiple papers with overlapping topics. A lack of outside citations means that a work has not generated interest from other publishing researchers, and this is unfortunate. It can have the practical effect that a paper essentially gets forgotten, particularly if the journal is not highly visible. Some high-quality papers do not get outside citations because people just don't notice them initially, and they end up being "forgotten" (i.e., not showing up easily in literature searches) and become more remote as the journal issue they were published in ages.
To respond to your title question, while it is possible that papers may essentially be forgotten if they fail to generate outside citations (and therefore become irrelevant in terms of influencing the profession), that does not mean that the researcher is "irrelevant". Academics perform teaching and service duties to the profession beyond our research, which are valuable professional outputs. We are also people with lives, families, etc., making us highly valuable and relevant to many people. If an academic is not successful at generating outside interest in their research, they are not "irrelevant".
Actually, it depends more on the work itself than the fact that it is only self-cited. But every truly new topic could have that characteristic for a while. If others are interested in the future, that will change.
But if a small subfield over a relatively long (whatever that means) time period fails to attract interest it will just disappear. Someone may resurrect it, of course.
Thinking about mathematics in particular, if someone came up with a new idea that depended only on "common knowledge", say, as published in text books, then there would be no need for citation to early work.
If no one cites you, it is, perhaps, harder to find your work since chasing backward citation links is an important way to discover things. If you are publishing in good (highly visible) journals, that may not be an issue in the short term.
But even things that make a clean break with the past (Einstein/Relativity) tend to cite things pointing out the differences and why the new thing is correct.
I am of the opinion that no problem really exists in isolation.
For every problem, one can identify at least three areas of interaction:
Even if only a small community cares about the problem per se, the tools available to address the problem are changing, as is the context of the environment in which the problem is being solved.
Even for highly theoretical mathematics, the problem does not exist in a vacuum: something caused the researchers to become interested, they are working on it in a world full of evolving potentially relevant methods, and something is causing them to stay interested despite the fact that they haven't solved it yet.
As such, I would be highly suspicious of a group of researchers who only engage in self-citation. They may have come to that point honestly, but it would still indicate a severe level of intellectual detachment from the rest of the scientific community.
Bottom line: even if nobody else cares about their work, they should care about other people's work enough to cite them.
To reiterate an important point already made in other answers, but, I think, deserving emphasis: it's not so bad to cite oneself, considering that (duh!) one's prior work could easily be background for one's current work, but to not cite anyone else is crazy... probably wildly inaccurate, etc. At the very least, setting the context by mention of prior art is a significant part of the interest of a new idea for me. To implicitly claim that there was no prior art is implausible, doubt-generating, and, at least, unhelpful.
I do confess that I did not understand any necessity of acknowledging prior art in my earlier years... Somehow the idea I'd gotten was to pretend to have the least indebtedness possible to other people. Well, this turns out to be ridiculous, in many ways.
So, again, the most silly/stupid aspect of only self-references is that it's surely just not accurate at all. Then, beyond that, ...
(So if I see a paper/preprint with all references to the authors or a limited circle of buddies, I am immediately suspicious...)
These days, when people judge researchers (especially hiring/grant committees, tenure boards, etc.) it is common to place much emphasis on impact. Impact is measured in a couple different ways, but all of them share the common idea that more people citing you is better.
If you only ever cite yourself, your citation count is 1. That is only one step up from the worst possible count, 0. So the debate of you citing your papers vs. the one other guy in the world who cares, is kind of dwarfed by the elephant in the room - namely that you're at the bottom. What difference does it make if you finish 99th or 100th, when only top 3 get a medal?
But given the obvious perverse incentive, usually self citations are not even counted as a full citation. Obviously you citing yourself is less interesting than a stranger citing you. In most modern citation metrics, self-citations are either scaled back with a factor, or disregarded entirely. When humans calculate an "informal impact factor" by Googling your papers, their brain will naturally apply such a factor as well. So it's like not only did you finish 99th, but you're tied for it as well.
In sum, I don't think anyone will care about whether you were cited by yourself or not, they will have already stopped caring when there is only 1 person citing you.
Incidentally, if you are the only one talking about your work, then you truly are irrelevant in the literal sense - nobody is finding you relevant to what they do. But I feel like that's putting it a bit harshly. Just because nobody has found your research relevant yet, doesn't necessarily imply that your research is inherently worthless and cannot possibly have bearing on anything else. It's just a heuristic after all. But that said, the academic community appears to be invested heavily in citation metrics for the time being, and as a result, having only self-citations will not impress many strangers.
There are some exceptional cases where I think a situation like you describe might be understandable:
But in my opinion, the effective solution here is not to split hairs, but instead to either broaden your work to have more relevance to people outside your narrow field, or start thinking about moving on to an allied field with broader appeal. That, or just accept that the world is not yet ready for your ideas, I suppose... Such is life.
In our tech-enabled, Alice-through-the-Looking-Glass Red Queen running faster and faster world, we keep on focusing on "impact" within a shorter and shorter timeframe. How many downloads did my paper have last week? How many citations did we get in the year since our last annual evaluation?
It's easy for genuine knowledge accomplishments to take their own sweet time, to sit on the shelf for quite a while before someone else integrates them or applies them to something else. Conversely, other ideas may flash in the pan, have tons of citations straight away, and then decades later be passé or just obviated since some other train of thought is more useful or broader in applicability. My dissertation in the 1990s made integral use of a result from the 1950s that had only one other citation, of the throwaway dead-end form "Somewhat similarly, X has shown that ..." (that nevertheless led me to it). And then my dissertation result was obviated by a more general approach by someone else a decade later.
So I would make no value judgment on a body of research that is ping-ponging in a very small enclosed room, even among its authors only, for even a number of years. I would make a value judgment on researchers who can't articulate why it could/should be of any interest to anyone at some yet-unknown point in the future -- even though I respect some purists would argue academic independence should allow "but I [researcher] find it interesting" should be reason enough.
The Nihilist Take
Your question seems to imply that relevance is absolute. It's meaningless to ask whether something is relevant without asking to whom it's relevant.
To answer your question directly, an isolated group of researchers whose work is never cited by anyone outside their circle is irrelevant to the rest of academia. But this is just a microcosm of academia as a whole. To non-academics, academia is irrelevant until their research has some practical application. On a cosmic scale, the endeavors of the entire human species are irrelevant. Ultimately, nothing matters. Look inward for justification and meaning, not outward.
Definitely not. The fact remains that, as long as you cite yourself and the citations are all relevant, you are not just ok, but you are progressing.
And it also happens that you may be doing research on a topic where not many people are active, except of course you yourself. In that case, it is but natural that your work will be full of self-citations.
Citation counts and origins are a poor measure of relevance.
If you are the only academic working on the history of basket weaving in northern elvish communities, you’re unlikely to be cited by academics working on dwarvish basketweaving, and unlikely to get lots of citation for that work, even if it’s highly relevant to northern elvish communities.
Contrarywise, if you publish a controversial theory - say old elvish basketweaving resulted in basket of greater strengths than dwarvish or hobbit baskets - you might get cited quite a bit, even if your work is irrelevant and possibly even wrong.
There is also the problem of timescale. The work of John Bell (of the inequality fame) was treated as “irrelevant” for a long while before it’s importance was recongnized.
