We sample it, and upon finding problems, adjust the system to eliminate that class of problems in the future.
Did you just create a new account so you could keep arguing with people?
Yes. HN is groupthink central, and enforces it through down votes, which marks the account as low quality, which then turns off commenting for that account. It is a classic negative feedback loop that enforces the groupthink. You can tell how many accounts I've created by the account number.