When is a broader scientific problem or question 'solved'?
Well, I think: never. But how this led to maybe a more interesting question....
We recently read a paper in journal club that started off by saying that a classical set of broad questions/ problems in soil microbiology had been ‘solved’. I think this is simply the wrong word to use. These were very broad questions, like when are soil microbes active in the environment; and while we certainly have addressed these questions, maybe also in some cases quite well, I feel that we haven’t solved them. I don’t even know what this could mean, solving such a broad question.
But I don’t want this to be a rant about semantics - this time! Because this actually led to an interesting discussion in lab meeting (thanks to Kostia for kicking it off). While maybe we can all agree that broad questions in science can never really be considered ‘solved’, maybe there is something like a plateau and a saturation level for that question. Yes, you can still find out more by using better techniques or maybe by looking at more specific details or by covering more of the parameter space in terms of ecosystems, soil types and geographical region (there are some well-known chronically under-researched part of this planet for soil and probably also other aspects of ecology). But maybe we have been accumulating a lot of knowledge so that now there are fewer gaps to fill and there is less new stuff to find out about this question or topic. It has reached something like saturation?
But how could we decide, how do we gauge the level of saturation? And if we could, what is the exact point at which there is enough known about something, 80% or 90% or 95% saturation, for whatever that means? And do we even need to decide, or will that decision be made by funding agencies or reviewers or editors who no longer consider further work on this topic sufficiently novel? Or, even another question: should we decide that enough is enough? Let’s move on to other things?
I think individual researchers can certainly make that call. If a field is becoming more mature, then, as the article we read correctly pointed out, it is the time for research synthesis, for example with meta-analysis. And maybe then it’s no longer the time to add yet another droplet to this particular river of science in terms of new experimental/ empirical work. It will simply also get increasingly difficult to ask new sub-questions on a given topic at some point of ‘saturation’, and maybe then it could be time to move on. Has anybody ever felt that way? I mean there is still a lot of quite exciting microplastic research going on, but I do also feel that it is already getting harder and harder to ask new questions on this topic, compared to when we started. But maybe it would be premature to say, let’s pack up and do something else, because a new method, a new concept, some new insight may yet open different opportunities. So I don’t think this is ‘solved’. Far from it.
When I think about this for myself, I don’t think my own personal interest is to research a topic to a point where it is exhaustively covered, I am much more interested in opening up new questions, and find new stuff to ask questions about, new problems. But there clearly are different approaches to science, equally valid, that aim for increasingly in-depth work on a particular topic. Maybe this mode of doing science is more common out there? I don’t know. Does anybody know?
But I digress. I think at the very least this is an interesting question to ask oneself. Has my topic reached anything close to ‘saturation’? Am I okay with that, or does this mean that now it is becoming just very hard to ask good questions. Or, alternatively, would you argue in favor of a point of view that with increased, increasingly detailed knowledge of something you can ask better and better questions? Has anybody ever done a ‘formal’ analysis of saturation of a question or field in the sciences? I think this will also depend on the level of generality of the problem or question, of course: a more general question is much more difficult to bring to saturation than a very specific one. Another one of these situations where it would be nice to have a resident philosopher of science on hand….
I’d be curious what you think about this. Please let me know in the comments.
Great questions! Philosophy says that truth is not attainable — it can be approached asymptotically, but never reached. There is also the matter of dynamics and emergence in complex systems, so that any system studied can all of a sudden do something you don’t expect, and you can’t predict the future of it. So, you get scientific revolutions, counterintuitive results, and lots of dissonance. To finally answer your question about whether to back up or go on, I think it makes sense to leave questions about one topic to future researchers, and explore what rocks your boat. There will never be a dearth of topics to further explore!!
The key word here is 'broader'. A narrowly defined question can be researched to exhaustion, whilst with enough tolerance a broad one can open up a series of new fields. Considering how the species of Carabus beetles originated and why are the stable is a question that was open 2 centuries back, that kept ticking on as geologists fed in scraps of data, and can be reopened and probably closed in the present day with DNA analysis. On the other hand it can be generalised into considering what are the conditions that either allow or prohibit the emergence of new species, in which case you have a hard scientific problem and an urgent practical issue as the world changes under human induced climate and environmental change.
The time scale does matter. We can exhaust our armoury of techniques and declare a topic fully researched, only to find it worth re-engaging as new methods emerge. Or, we can treat the incremental gains in our knowledge too small to be worth the effort, until a social change makes every small gain a headline, e.g. advances in battery technology.