

Ask PG: Is d(users)/dt constant on HN? - frisco

Eternal September wasn't so much an issue of "too many users" as "too many new users that couldn't be taught local customs before they overwhelmed said local customs."  If it isn't roughly constant, especially over longer periods (i.e., quarter-over-quarter growth), you could work out when either you'd expect HN to fall victim to an Eternal March (demo day + applications = lots of press and spike in users?), or when you'd need to work out a different new user welcoming process?
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pg
It looks like it's slightly steeper than flat. At least so far. Growth should
flatten out at some point.

It's hard to predict social phenomena. I just try to react quickly when
problems arise.

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ivankirigin
If frisco is correct, that sites degrade because of a too high rate of growth,
this presents an extremely simple way to prevent that: rate limit new account
creation.

You could cap it right now, and see what happens to the quality of the site.

~~~
jurjenh
This seems like a very good idea in terms of controlling spikes in comments -
but you have to question whether this is the (main) cause of the degradation.

If limiting new accounts seems like the best solution, it should be done
clearly and transparently - as the users you are trying to weed out are
generally fickle and will not stay, so won't bother to check / sign up later.
Let users know the reason why they can't sign up now, and when they should be
able to.

However, users that have a legitimate need to comment (eg site / app owners)
need to be allowed access - solving this could be trickier.

~~~
ivankirigin
Let people input an email to be pinged when a spot in the queue opens up. Most
people won't.

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Travis
PG - any chance that you guys are planning on releasing quarterly high level
reports from HN? I did some searching for it, but couldn't find anything in
the past (I'm a fairly recent user, but couldn't find any references). It'd be
interesting in a navel-gazing sort of way to see what the HN crowd looks like.

Also, a lot of HN discussions are self-referential (esp. when discussing user
testing, etc.). It would be really helpful to have some data to add to these
discussions.

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leaker
It looks like some people were simultaneously banned following that thar'
flamewar (a bunch of posters disappeared at the same time, and there's
chatter) so d(users)/dt can be negative.

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ekpyrotic
leaker, d(users)/dt can be negative without bannings.

d(users)/dt is growth in users, not their number. To illustrate: if 600 users
registered in February, then only 400 in March HN's growth would be negative;
d(users)/dt would be negative.

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PieSquared
Erm, wouldn't that be the second derivative?

d(users)/dt would be the rate of change of users. That can only be negative if
the amount of users decreases, ie through bannings.

You're thinking of the second derivative, d^2(users)/dt^2, which is the rate
of change of the rate of increase of users. If that is negative, it means that
the growth has slowed down, as in your example with February and March.

~~~
frisco
I was asking about the second derivative; if d(users)/dt wasn't constant, then
d^2(users)/dt2 is nonzero and eternal september risk is fairly high (assuming
HN isn't shrinking). If you assume idealized user growth (which doesn't happen
-- there are so many people in the end that would care to either join HN or
troll HN), then eternal september is actually guaranteed if d^2(users)/dt2 >
0, since there will come a time t when (new users) > (old users).

