Thursday, September 11, 2008

Random Musings on is a site by programmers and for programmers, whose purpose is answering questions on topics relating to software development. At the time of this writing it has completed a closed beta test and is in a more extensive test phase, ramping up to open on September 15, 2008. Access to the beta site is open to anyone who wants it during the test period, see for details.

Stackoverflow is the brainchild of Jeff Atwood and Joel Spolsky, long-time bloggers on software development topics. It is described by its creators as the intersection of a Wiki, blog, forum, and digg/reddit voting site. Users post questions and answers about programming topics, and the questions and answers are voted on by the community. The highest voted answers rise to the top.

Incentives, aka upvoting

The site has a series of incentives to keep people coming back. The biggest incentive is the reputation score, which goes up and down depending on how other users rate your questions and answers. Reputation encourages asking questions and providing answers, in order to improve ones score.

reputation Reputation is in many ways similar to the Karma awarded by and Hacker News. Capabilities on the site are unlocked by having a high enough reputation. For example voting on posts requires a score of 15 or more, where new users start with a score of 1.

The other, more unique rewards system on stackoverflow are the badges. Badges are directly modeled after the achievements awarded in Xbox games, which encourage gameplay by granting an award when a level is completed or other objectives achieved. The achievements show up in a gamers profile on Xbox Live, where they are used to talk smack about opponents.

badges The stackoverflow badges encourage exploration of the features of the site. The first few badges area easy to obtain: fill out your profile to obtain the Autobiographer badge, vote up to get the Supporter badge, and gain the Teacher badge by asking a question which is voted up. Later badges get harder, requiring larger numbers of users to vote on your submissions.

Are these mechanisms effective? I think the reputation score is, certainly. As in a video game, there is a certain thrill to seeing ones score go up. The badges seem, well, hokey to me. I'll grant that I'm probably not the target demographic anyway, badges might have more resonance with those who play games regularly.

Content question votes

The questions during the stackoverflow beta have ranged widely, but by far the most common questions are about Microsoft topics like .Net and SQL Server. This is likely a reflection of the audience of Jeff and Joel's respective blogs being heavily invested in these technologies.

I've been pleasantly surprised by a number of the questions posed on the site. Where the programming sub-reddit is now completely dominated by Ruby, Python, and Haskell, stackoverflow is covering a much wider mix of technologies. There have even been a few embedded system and assembly language questions.

Technical solutions to social problems

The history of web communities dedicated to software developers has not been pretty. The comment section of the programming sub-reddit is now so filled with vitriol and casual slander as to be unpleasant to read, let alone participate in. Hacker News attempts to prevent this slide into toxicity by a combination of social pressure and technical measures like not allowing downvotes until a certain karma has been achieved.

Stackoverflow is relying heavily on technical solutions to social problems. For example:

  1. Downvotes are only allowed by those at higher reputations, and reduce the target reputation by two where an upvote adds ten. Additionally downvoting costs the voter one point of reputation, to discourage frequent use.
  2. To discourage trivial edits to bump a question to the top of the list, more than five edits to a post make it "community owned" and no longer grant reputation to its poster.
  3. Users with sufficiently high reputation can edit another users posts or comments, for example to remove mean-spirited remarks. It is hoped they will use these powers for Good and not Evil.
  4. Users can mark a question or answer as offensive. This does not merely signal a moderator; if enough users click offensive the question will be automatically removed.

Speed bumps coming

I really like the premise behind stackoverflow, of a social media site designed specifically for programmers. I think there is definitely a need which reddit, DZone, and other developer-focussed sites do not fill.

Editing another users post

However I think this initial iteration of stackoverflow has a psychological problem: it tries to simultaneously be a voting site like reddit and digg, and a community site like Wikipedia. What you end up with is postings associated with a particular users name, and which provide benefits in the form of reputation, but which can be edited by other users. The site attempts to ameliorate this by making a post "community owned" after five edits, so it no longer belongs to the posting user. This step function solution brings the opposite problem: the poster feels cheated out of the reputation from what has become a popular topic.

This mismatch between the digg and wikipedia models is not working smoothly yet, in my opinion. The digg model thrives on ownership, the wikipedia model on anonymity.

Some other thoughts about future issues:

  • On other sites even replying to someone else's comment can elicit a defensive reaction. I suspect that editing another user's question or answer on stackoverflow will lead to a series of edit-revert-edit-revert struggles.
  • There is an enormous incentive to answer quickly: the early answers accrue upvotes and gain significant inertia to accrue more upvotes. A number of users answer immediately by quoting Wikipedia or the first Google result, and gain significant reputation by doing so. stackoverflow will have difficulty succeeding if the highest rated answers are mostly Wikipedia rehashes.
  • The site is far more active during US business hours, and relatively idle during nights and weekends. When combined with the strong incentive to answer immediately, the site can become a productivity drain. We may see companies block stackoverflow in the same way that Facebook is often blocked.


I really like stackoverflow, and I want it to succeed. I think its business model is sound: focus on a well-defined niche, provide real value, and carefully select advertising to target that specific audience.

UPDATE: This article was picked up on reddit, with amusing commentary. Also Sara Chipps and Dan Dyer have written about their initial impressions of stackoverflow.