I’m unsure of whether this should be a blog post or an article, so I’ll probably make it both. I’ve probably written most of it before in Stack Overflow answers, but as I couldn’t find anything when I was looking earlier (to answer a question about Stack Overflow answers – now deleted, so only available for those over 10k rep) I figured it was time to write something in a medium I had more control over.

This is not a guide to getting huge amounts of reputation on Stack Overflow. As it happens, following the guidelines here is likely to result in decent rep,  but I’m sure there are various somewhat underhand ways of gaining reputation without actually being helpful. In other words, I’m not going to explain how you might game the system, but just share my views on how to work with the system for the benefit of all involved. A lot of this isn’t specific to Stack Overflow, but some of the advice isn’t applicable to some forums.

Hypocrisy warning: I’m not going to claim I always follow everything in this list. I try, but that’s not the same thing – and quite often time pressures will compromise the quality of an answer. Oh, and don’t read anything into the ordering here. It’s how it happened to come out, that’s all.

Read the question

All too often I’ve written what I thought was a great answer… only to reread the question and find out that it wasn’t going to help the questioner at all.

Now, questions are often written pretty badly, leaving out vital information, being vague about the problem, including lots of irrelevant code but leaving out the crucial bit which probably contains the bug, etc. It’s at least worth commenting on the question to ask for more information, but just occasionally you can apply psychic debugging to answer the question anyway. If you do have to make assumptions when writing an answer, state them explicitly. That will not only reduce the possibility of miscommunication, but will also point out the areas which need further clarification.

Code is king

I can’t believe I nearly posted this article without mentioning sample code.

Answers with sample code are gold… if the code is appropriate. A few rules of thumb:

• Make sure it compiles, assuming it’s meant to. This isn’t always possible – for example, I often post at work from a machine without .NET on it, or on the train from a laptop without Java. If you can’t get a compiler to make sure your code is valid, be extra careful in terms of human inspection.
• Snippets are okay, but complete programs rock. If you’re not already comfortable with writing short console apps, practise it. Often you can write a complete app in about 15 lines which doesn’t just give the solution, but shows it working. Imagine the level of confidence that gives to anyone reading your answer. Get rid of anything you don’t need – brevity is really helpful. (In C# for example that usually means getting rid of [STAThread], namespace declarations and unused using directives.)
• Take a bit of care over formatting. If possible, try to prevent the code wrapping. That’s not always realistically feasible, but it’s a nice ideal. Make sure the spacing at least looks okay – you may want to use a 2-space indent if your code involves a lot of nesting.
• If you skip best practices, add a comment. For example, you might include // Insert error handling here to indicate that production code really should check the return value etc. This doesn’t include omitting the STAThread attribute and working without a namespace – those are just reasonable assumptions and unlikely to be copied wholesale, whereas the main body of the code may well be. If your code leaks resources, someone’s production code may do so as well…

Code without an explanation is rarely useful, however. At least provide a sentence or two to explain what’s going on.

Answer the question and highlight side-issues

Other developers don’t always do things the way we’d like them to. Questions often reflect this, basically asking how to do something which (in our view) shouldn’t be attempted in the first place. It may completely infeasible, or it may just be a really bad idea.

Occasionally, the idea is so awful – and possibly harmful to users, especially when it comes to security questions – that the best response is just to explain (carefully and politely) why this is a really bad thing to do. Usually, however, it’s better to answer the question and give details of better alternatives at the same time. Personally I prefer to give these alternatives before the answer to the question asked, as I suspect it makes it more likely that the questioner will read the advice and take it on board. Don’t forget that the more persuasive you can be, the more likely it is they’ll abandon their original plans. In other words, “Don’t do this!” isn’t nearly as useful as “Don’t do this because…”

It’s okay to guess, but be honest

This may be controversial. I’ve certainly been downvoted twice on SO for having the temerity to post an answer without being 100% sure that it’s the right one – and (worse?) for admitting as much.

Sometimes there are questions which are slightly outside your own area of expertise, but they feel an awful lot like a situation you’ve been in before. In this kind of case, you can often write an answer which may well help – and would at least suggest something for the questioner to investigate a a possible answer to their problem. Sometimes you may be way off base, which is why it’s worth explaining in your answer that you are applying a bit of educated guesswork. If another answer is posted by an expert in the topic, it may well be worth the questioner trying their solution first… but at least you’re providing an alternative if they run out of other possibilities.

Now, somewhat contradictory…

Raise the overall accuracy level

It should go without saying that a correct answer is more helpful than an incorrect one. There are plenty of entirely inaccurate answers on Stack Overflow – and on newsgroups, and basically every online community-based resource I’ve ever seen. This isn’t surprising, but the best ways to counter it are:

• Challenge inaccurate information
• Provide accurate information yourself

One of the key aspects of this is to provide evidence. If you make an objective statement without any sort of disclaimer about your uncertainty, that should mean you’ve got good reason to believe you’re correct. That doesn’t necessarily mean you need to provide evidence, but as soon as there’s disagreement, evidence is king. If you want to assert that your code is faster than some other code, write a benchmark (carefully!). If you want to prove that an object can be collected at a certain point in time, write a test to show it. Short but complete programs are great for this, and can stop an argument dead in its tracks.

Another source of evidence is documentation and specifications. Be aware that they’re not always accurate, but I generally believe documentation unless I have a specific reason to doubt it.

Provide links to related resources

There have been a few questions on Stack Overflow as to whether it’s appropriate to link to other resources on the web. My own opinion is that it’s absolutely appropriate and can add a lot of value to an answer. In particular, I like to link to:

• MSDN and JavaDoc documentation, or the equivalent for other platforms. With MSDN URLs, if they end in something like http://msdn.microsoft.om/foo(VS80).aspx, take the bit in brackets out of the URL (leaving http://msdn.microsoft.om/foo.aspx in this case). That way the link will always be to the most recent version of the documentation, and it doesn’t give WMD as many problems either.
• Language specifications, in particular those for C# and Java. I generally link to the Word document for the C# spec, which has the disadvantage that I can’t link to a specific section, and it won’t just open in the browser. On the other hand, I find it easier to navigate than the MSDN version, and I’ve seen inaccuracies in MSDN.
• My own articles and blog posts (unsurprisingly :)
• Wikipedia
• Other resources which are unlikely to become unavailable

The point about the resources not becoming unavailable is important – one of the main arguments against linking is that the page might go away in the future. That’s not a particularly compelling argument for most reference material IMO, but it is relevant in other cases. Either way, it’s worth including some sort of summary of what you’re linking to – a link on its own doesn’t really invite the reader to follow it, whereas a quick description of what they’ll find there provides more incentive.

One quick tip: In Chrome I have an MSDN “search engine” set up and in Firefox a keyword bookmark. In both cases the URL is http://msdn.microsoft.com/en-us/library/%s.aspx – this makes it easier to get to the MSDN page for a particular namespace, type or member. For example, by typing “msdn system.io.fileinfo” I get straight to the FileInfo page. It doesn’t work for generics, however. At some point I’d like to make this simpler somehow…

Care about your reader: spelling, grammar and style matter

I’m lucky: I’m a native English speaker, and I have a reasonably good natural command of English. Having said that, I still take a certain amount of care when writing answers: I’ll often rewrite a sentence several times until I feel it works. I’ve noticed that answers with correct spelling and grammar are generally upvoted more than ones with essentially the same content but less careful presentation.

I’m not recommending style over substance; I’m saying that both are important. You could be putting forward the most insightful comment in the world, but if you can’t communicate it effectively to your readers, it’s not going to help anyone. Having said that…

A time-limited answer may be better than no answer at all

I answer Stack Overflow questions in whatever spare time I have: waiting for a build, on the train, taking a break from editing etc. I frequently see a question which would take a good 15 minutes or more to answer properly – but I only have 30 seconds. If the question already has answers, there’s probably no sensible contribution I can make, but if the question is completely unanswered, I sometimes add a very short answer with the most important points I can think of at the time.

Ideally, I’d then go back later and edit the answer to make it more complete – but at least I may have given the questioner something to think about or an option to try. Usually these “quickies” are relatively fruitless, but occasionally I’ll come back to find that the answer was accepted: the slight nudge in the answer was all that was required. If I’m feeling diligent at that point I’ll still complete the answer, but the point is that a brief answer is usually better than nothing.

Don’t be afraid to delete (or edit heavily) useless answers

It’s almost inevitable that if you post enough answers, one of them will be less than helpful. It may start off being a good one, but if a later answer includes all the information from your answer and more, or explains it in a better way, it’s just clutter.

Likewise if you make a wild stab in the dark about the cause of a problem, and that guess turns out to be wrong, your answer could become actively unhelpful. Usually the community will let you know this in comments or voting, but sometimes you have to recognise it on your own.

Be polite

It’s a shame that I have to include this, and it’s even more of a shame that I need to take better notice of it myself. However boneheaded a question is, there’s no need to be rude. You can express your dismay at a question, and even express dismay at someone failing to read your answer properly, without resorting to inflammatory language. In the end, no-one really wins from a flame war. Remember that there’s a real person at the other end of the network connection, and they’re probably just as frustrated with you as you are with them. If things are getting out of hand, just write a polite note explaining that you don’t think it’s productive to discuss the topic any more, and walk away. (This can be surprisingly difficult advice to heed.)

Next time I get too “involved” in a question, could someone please direct me to this point? And don’t take “But I’m right, darnit!”  as an excuse.

Don’t “answer and run”

Sometimes an answer is very, very nearly spot on – but that final 1% is all the difference between the reader understanding fully and having a dangerous misunderstanding of the topic.

Stack Overflow makes it pretty easy to see comments to your answers: monitor this carefully so you can respond and clarify where appropriate. Many web forums have an “email me if this thread is updated” option – again, this is useful. It’s really frustrating (as a questioner) to be left hanging with an answer which looks like it might solve a real headache, if only you could just get the ear of the author for a moment.

Having said all of this:

Have fun

In my experience the most useful users are the ones who are obviously passionate about helping others. Don’t do it out of some misguided sense of “duty” – no-one’s paying you to do this (I assume) and no-one can reasonably complain if you just haven’t got the time or energy to answer their question. Save yourself for a time when you can be more enthusiastic and enjoy what you’re doing. Go ahead, have a cup of coffee and watch a Youtube video or something instead. You don’t have to check whether there are any new questions!