# What do we do with rapidly evolving subjects?

Some topics and subjects in TCS are evolving and changing fairly rapidly. For example, I'm interested in SAT, particularly in the best upper bounds. Now, there are questions on this site concerning this, but they are around 3 1/2 years old. I'm very interested in what changes have taken place in the last years, but I've been sort of "out of the loop". What I mean to say is that this site is one of the main places I go to keep up-to-date. So I'm wondering what I can do to get up-to-date information on 3-SAT and especially #3-SAT's upper bounds.

If we had infinite freedom to do what we want on this site I would ask the same question again. But I'm wondering if there is maybe some other way to get current information.

So what do we do when we'd like to re-ask questions?

• I don't know the answer to this, but I think it is a very important discussion to have. One thing I can suggest that would work within the current rules, would be to open a bounty on that question saying that you are asking for more recent results. However, I hope we can come up with a better procedure after some discussion. – Artem Kaznatcheev Feb 1 '14 at 23:03
• @ArtemKaznatcheev: I think I'd gladly offer a bounty for a good response. Additionally, and this may be quite a stretch, we could perhaps, somehow append a new question to an old one. – Matt Groff Feb 1 '14 at 23:30
• It's probably best to find a solution within the system, as getting stackexchange software changed would likely be difficult. – Lev Reyzin Feb 2 '14 at 2:11
• I wonder if an update tag would be out of the question. – Matt Groff Feb 2 '14 at 2:23
• There are some example for similar situation, e.g TSP recently (last 2 years), had very improvement in approximation algorithms, and this question, answered by OP and if someone found new result added to the selected answer to keep it update. You could also improve current available answer with new results, or add new complete answer (community wiki style) as summary, to keep it update all the time. – Saeed Feb 2 '14 at 14:02
• If the answer you are looking for will be an answer to the older question then I don't think posting a new question is the standard way to go. You essentially want an update to its answers. I think a bounty is the standard way. Update tag is not a good solution at all. A reasonable edit to the question to bring it to g the front page can be also OK I think. – Kaveh Feb 2 '14 at 15:40
• If you can phrase your question in a natural way that it has different answers that can be also OK. – Kaveh Feb 2 '14 at 15:46
• agreed there is sometimes little knowledge/attn on the site to old questions even though there may be new applicable results to them [se tries to encourage this with some badges eg "revival" but its part of nature of system that old questions are forgotten & serve more as archives]. suggest just rephrasing the question attempting to take into acct new results & trying to be specific as possible, try to incorporate new angle or some "twist" not in the old question that shows some new effort on your part... – vzn Feb 2 '14 at 16:25
• @Kaveh I was going to suggest something more radical after thinking about it for a bit. Why not create a new question (with a link to the old) and then close the old one as a duplicate of the new one? – Artem Kaznatcheev Feb 5 '14 at 5:49
• @Artem, I would prefer the older one to remain open, I don't think closing it because someone wants an update to its answers is a good idea. I think it is more reasonable that the new question be posted and after a while get closed as duplicate of (and maybe even merged with) the old one. At the end the point is to bring attention to the old question and the fact that its answers need an update. – Kaveh Feb 5 '14 at 6:50
• @Kaveh I suggested closing the older one as duplicate because that way it has a link to the newer one (which is really what a person would be looking for if they want the state of the art). Also, because it seems like less work than keeping track of the new question and merging. However, I do understand that people sometimes view "closing" a question as a statement that "you did something wrong" and that is not the message we want to send to the original asker. – Artem Kaznatcheev Feb 6 '14 at 5:43

Start a bounty on the old question, with the reason "Current answers are outdated".

• That doesn't work. How would sombody know that the existing answer was outdated unless they knew what the current situation was? And, in that case, wouldn't they just add a new answer to the old question saying, "In the last X years, things have changed and now, ..." It seems that Matt actually wants to know whether the old answers are out of date or not. – David Richerby Feb 5 '14 at 10:07
• @DavidRicherby: "Outdated" in the sense that "they were posted in 2010 and they don't tell what (if anything) has happened since then". – Jukka Suomela Feb 5 '14 at 10:37

I just put a small bounty on the question with a custom message to demonstrate how to use the bounty feature for updates:

Best Upper Bounds on SAT

• Thank you Kaveh! I'm really curious to see how the question proceeds. It looks like the majority of the votes now are for this type of bounty. – Matt Groff Feb 8 '14 at 1:23
• @Matt, so far it seems to have worked. By the way, another possible option is to do what was implied in one of the comments: look up papers which cite the best previous answers, it is rather easy to do so using say Google scholar (and then of course post a new answer if there has been any improvement :). – Kaveh Feb 12 '14 at 12:42

Can you give an example of a specific question ? It might be possible to construct a new question that references the old one but still asks for something different. If the question is merely "what's happened in this topic since the last question", that's already too vague to be a reasonable question with a definite answer.

• Unfortunately, I think I'm after "what's happened since the last question". I'm after the upper bounds on SAT. We have: cstheory.stackexchange.com/questions/1060/…" - this question on SAT. It's been roughly 3 1/2 years, so there may have been improvements since then. – Matt Groff Feb 2 '14 at 14:37
• Hmm. I can imagine this kind of thing appearing often. And it would be neat if some questions maintained continued updates (like on a TSP-related question). Maybe the best thing is to post a bounty and a clarification as to why ? – Suresh Venkat Feb 3 '14 at 3:19

Here is an easy solution, edit the question and ask specifically for most up-to-date information.