This is a short article detailing my thoughts on the recently released
programming Q&A site, Stack Overflow.
Background
Historically, I've had three resources for programming questions:
Over the course of 80 days, I've found Stack Overflow to be a better resource
than all three of the above, even when combined.
The way I see it, Stack Overflow (hereby referred to as SO) is going strong for
two fundamental reasons:
SO baited the right community with the appropriate timing
SO uses tags
Community
If you think about it, there's nothing about SO that ties it to programming
questions, aside from the constitution. (On SO, the constitution is the site
FAQ). All in all, SO is a Q&A framework. If it's just a Q&A framework, how
did SO manage to stay on topic and under control from its inception? They took
the right members in with the right timing.
The beta test population was roughly given by the following:
- Podcast listeners
(Jeff's readers UNION Joel's readers) - the relatively uninterested -
attrition
- Beta testers
(Podcast listeners INTERSECT people that cared enough about the
programming Q&A site to find an obscure signup form) - more attrition
Joel Spolsky and Jeff Atwood are both well-known in the blogosphere among
readers interested in improving their programming skills and doing software the
Right Way. Beginning with their reader base (already amenable to their cause)
there were two significant levels of filtration, as reflected in the above
pseudo-formulae, that ensured that SO started off with a group of people who a)
cared and b) had a significant body of knowledge with respect to programming
and good software practices. This is just the kind of constituency that you
want to impart some positive momentum on a fledgling Q&A site.
The private beta provided an adequate growth period so that, at release, there
were enough core members with a solid conception of the constitution that
they helped to create. Additionally, the core was able to uphold the tenets of
the constitution with power from the reputation that they built. (If there were
a third reason for the site's success, it would be how empowered the high-rep
members are to uphold the constitution.)
If SO had been released to the public in a Hollywood Launch, without the
beta momentum they had, I believe it would have failed. The framework is not
programming-specific — the community is.
Tagging
The site happens to be particularly well designed for programming questions in
its tag-centric model. SO is a big pipe for programming questions with an
unlimited number of virtual channels, each of which is denoted by a tag. With
recently added capabilities to ignore or flag particular virtual channels, you
(subtractively) take only the content that you want from the big pipe and
prioritize the results. Exactly how nice this capability is will come to light
when comparing SO to the other programming question outlets.
The tag model is also particularly well suited to the structure of knowledge in
the programming domain, where the interests of individual constituents have a
strong tendency to straddle several subdomains. Anecdotally, this is especially
true for those who really care about their craft: the best programmers tend to
have a great deal of depth to their knowledge, which inevitably ends up
overlapping with other areas of interest. For example, most of today's great
programmers use version control systems, convey information effectively through
documentation, and recognize/employ design patterns. Many great programmers
also understand than one programming paradigm and program in more than one
language. When you mix a number of these programmers together, you get some
really strong sauce. The tag system allows these members to cut out the noise
and exchange information in their subdomains of expertise.
Community again: noobs
Don't take my subliminal messaging the wrong way: the noobs help. As they say,
everybody starts out as a noob. It's clear that noobs pave the way for many
others to follow by asking their noobish questions — that's rarely disputed.
The really interesting thing is that noobs can provide a more brute force
approach to answering questions correctly.
So long as the noobs are semi-informed, they're probably on SO because they're
trying to learn about a topic of interest. Active learning processes are
accompanied by reading and revisiting things that the more seasoned veterans
haven't cared to think about in a long time. Noobs, with references fresh in
their mind, can offer up suggestions or quotations (which they may or may not
fully understand) while the rest of the members determine whether or not their
information is helpful via votes and comments. Even if the noob's proposed
answer is somehow incorrect, other members will learn exactly why. If other
members thought the noob's answer was feasible as well, they'll be informed and
corrected by seeing the dialog. This isn't something you get on an
experts-only-answer site: interpolation of the truth through the correction of
proposed answers.
There is, of course, the potential for Noobs of Mass Destruction (NMDs?) a la
the Eternal September. If noobs outweigh the properly knowledgeable
constituency so heavily that misconceptions are voted up far more rapidly than
proper solutions, the site will suffer from a misinformation-shock. This
misinformation may be corrected over time, but aside from Accepted Answers it's
difficult to jump a correct answer to the top over highly up-voted incorrect
answers. You need a critical mass of users that know what they're talking about
to tip the scales with their votes and their arguments.
Lucky for us members, this didn't happen at public release. Even more lucky for
the world of programmers, the success of the site and lack of an Eternal
September-like phenomenon on SO will lead to more informed programmers from
here forward, further reducing the chance for SO's quality to deteriorate.
Really, it was just the initial gamble of going public and, as I mentioned
before, SO got the timing right.
Community scaling through tagging
One of my favorite parts of all this is that tags allow the community scale
beautifully. If SO gains a thousand new C# programmers as members, does that
hurt, say, the Python programmers? No: because of tags, more members can only
mean a better site. "Stack Overflow is biased towards C#" is not a self
fulfilling prophesy. I'll explain why:
For argument's sake, let's say these are C# robots who only understand ways to
use C# syntax to do what you want (i.e. "You can use regions to ease generated
code injection. Beep."). If I'm a Python programmer who doesn't care about C#,
I'm ignoring the tag anyway and don't get inundated with noise from the robots.
Inevitably, our hypothetical is incorrect and the C# programmers will all have
knowledge which crosses into other subdomains. In the (slightly more
realistic) case that the members are human beings who know C# along with some
generic principles of programming and software design, they can only
assist me in my cross-domain problems.
More C# programmers can only help the Python programmers. For all X and Y, more
people interested in X can only help people interested in Y, so long as
everybody tags everything appropriately. Except Lisp.
Comparison to other outlets
How does SO stack up against the alternatives? The primary differentiation
comes in a few identifiable areas:
SO is structured. The framework provides incentives for helping others,
an intentionally limiting structure for threads of conversation, and
visibility of unanswered questions/questions of interest.
SO is asynchronous. Information is aggregated as members have time to ask
or answer questions, with a clear record of which questions have been asked
and what answers have been provided.
SO is centralized. The site is a one-stop-shop for all programming
questions, broken into virtual channels via tags. SO consolidates programming
question information across subdomains. User visibility spans subdomains. There
is a centralized search capability that allows you to restrict by virtual
channel(s).
SO is persistent. All questions and answers are permanently stored and
indexed for future reference.
Structured
Folks on IRC, Usenet, or your buddy list have no real incentive to help you
beyond the goodness of their hearts. I'm a starry-eyed idealist and I'm happy
that this has worked historically, but it's readily apparent that people love
playing for points. SO is one of those purely healthy forms of competition
where everybody seems to win; from what I've seen, RTFM and "Google is Your
Friend" trolls are consistently down-voted! The reputation system also appears
to increase the responsiveness of the site — everybody is looking for the
quick "Accepted Answer" grab if they can get it. I had figured that people
would try to game the system, but it seems like most people with reputation
have been sane, and the people with little reputation have their teeth pulled
appropriately. Kudos to the karma system.
What differentiates SO from a big bulletin board is the three-tier threads. You
have question (Original Poster), answer (many answers to one question), and
comments (many comments to one answer). @replies allow for infinite "virtual"
threading, but there's a clear indication of how the conversation is supposed
to take place through the structure of the site. My experience with this format
has led me to believe that it's ideal for removing noise from the answer tier
(via short comments), without letting the meta-conversation get too crazy.
Threading on Usenet allows you to explore related topics of conversation with
less friction, but it can be a big problem when you just want to know the
answer that the Original Poster (OP) finally accepted. You often see such
sub-conversations on Usenet get turned into new threads, while SO asks that you
form the new thread pre-emptively as a new question. I have no problem with
SO's approach, given the benefits of the three tiered conversation and the more
precise indexing capabilities that result from structured threads.
Visibility of questions and answers is a big problem on IRC: there's a distinct
fire-and-be-forgotten phenomenon in most channels, proportional to their noise
level. Additionally, there's usually a few super gurus in each channel that can
only handle one or two problems at a time, leading to,
[impatient-43/4] Can anybody answer my question^^!?!?
messages ad nauseum.
Asynchronous
Usenet does better than IRC in terms of question visibility because it's an
asynchronous medium. IRC's synchronous format makes help a lot more
interactive, but at great cost. In addition to the fire-and-be-forgotten
phenomenon, you inevitably juggle O(n) synchronous channels
simultaneously, where n is the number of topics you're interested in.
Also, remember that chat is exactly that: you're going to get unwanted noise.
Other people's Q&As, off topic conversation, and sometimes spammers all
interfere with your ability to communicate a problem and get an answer in real
time. If you've ever tried reading an IRC log to determine the answer to your
question, you probably understand this principle — once you mix anonymized
handles in with a many-to-many conversation, you give up quickly.
The asynchronous model fits into everybody's day more nicely and scales much
better. I haven't yet seen a question on SO where I said to myself, "This Q&A
could have benefited greatly from an increased level of synchronous
interaction." (Yeah, that's really how I talk to myself. Wanna fight about it?)
Centralized
As I mentioned, the big pipe is a beautiful thing. Some nice corollaries are:
A single, unifying constitution that prevents you from taking flak (from
trolls or disgruntled people) and remembering various sets of rules.
You avoid redundant work because it's easy to point somewhere else in the
same big pipe.
Subscribing to topics you care about and are knowledgeable in scales more
easily across topics.
You end up with more eyes per channel because because it's easy to subscribe
across topics.
One could argue that IRC's Freenode is similar in the virtual channel respect,
but logging is certainly not centralized, and listening to many virtual
channels simultaneously quickly converges to impossible. Unlike SO's multi-tag
view, asking a question in one IRC channel is unlikely to get the attention of
people who reside in other channels.
Newsgroups are all-over-the-place decentralized. It's definitely a web 1.0
technology. There's a bunch of services that consolidate information for
newsgroups of interest (Google Groups, gmane), but due to the information being
replicated all over the web, the page rank for a given Q&A will tend to be
weaker as it's divided across the resources and components of the thread.
Newsgroups don't tend to play together as nicely as SO tags — it's easy to see
how a question like, "What's monkeypatching?" could be asked on
comp.lang.python, comp.lang.ruby, and so on, without ever being referred to
each other.
On SO, if you tag things properly, information naturally crosses virtual
channels and is well indexed for search.
Persistent
IRC channels tend to get inundated with the same questions over and over, so
they make an FAQ to persist a subset of the information that's routinely
provided in the channel. Taken to its rational extreme, you could persist all
the Q&A information in such a manner, in which case you'd have SO.
Some IRC channels get logged, but I rarely care where the logs are — there's
little hope of you finding the answer from the log (as previously discussed).
It's also unlikely that the page rank of any given log will be significant. In
my IRC experience, you keep your own chat logs if you really care to find the
conversations later on. In any case, this is much less elegant than SO's
centralized and indexed persistence capabilities.
As I mentioned before, newsgroups have persistence, but it's not well
centralized or indexed. Persistence is a moot point if you can't find what
you're looking for.
Critical Thinking
Since I'm out of a job as a karma system and NMD doomsayer, I've got to talk
about the potential for secondary Armageddon-like effects.
SO doesn't have a significant enough differentiation from refactormycode.
Its mission is well differentiated, but it seems like the permitted content
on SO is a superset of what can be found on refactormycode. I would consider
this kind of Q&A noisy, but it certainly follows the same general format. It's
possible the authors are cool with SO engulfing a lot of refactormycode
material, but in that case I hope we get some better large code block
support. If SO doesn't want it, it should be in the constitution.
I'm concerned about question staleness. Over time we'll see how venerable the
Q&As are, but my immediate concern is the plot of views over time: is the
drop off in number of views over time for a given question so significant that
the return rate cannot overcome initial misconceptions? If misconceptions are
introduced later, will users still be watching the thread? There's no "watch
this thread" capability in SO for push notification, so to some extent the
system expects you to check back at regular intervals to monitor activity on
threads. This may be an unrealistic assumption. To be fair, the constitution
explicitly states you may re-ask a question if you acknowledge that the other
exists, which may prevent this from being such a big deal.
I'm curious as to how the number of non-programming, technical questions has
trended over time. Potential problems in this area are alleviated by the
constitution and the fact that sufficiently reputable members can close threads,
but it's easy to see how there will be an inevitable flow of system
administrative questions due to how knowledgeable the constituency is. If the
site didn't have such good safeguards, it would easily swallow a whole lot of
other Q&A domains that are indirectly programming related.
