Interesting. What kind of patterns have you tried to look for?
One source of "randomness" in user voting on time-sensitive sites (as opposed to e.g. a forum where you could log in once per day and read up on everything) is that the oline audience changes troughout the day as different timezones are at work / asleep / etc. This is both a regional change as well as an occupational/age change.
I discovered letting Europe see it a few hours before the USA woke up was the best time of day. A post needed a few upvotes before the 'bury brigade' saw it.
One source of "randomness" in user voting on time-sensitive sites (as opposed to e.g. a forum where you could log in once per day and read up on everything) is that the oline audience changes troughout the day as different timezones are at work / asleep / etc. This is both a regional change as well as an occupational/age change.