...so when should I post it?
Every time I, or anyone, posts a DailyKos statistics diary, that question inevitably gets asked. That question has always been answered by "we don't really have the data to say for sure". Until now...
The Institute for Excessive Daily Kos Meta-Analysis brings you "1 week in the life of the Recommended List".
Once again, this analysis wouldn't be possible without jotter and his wonderful lists. In this case, he kindly modified his system to track the Recommended list in addition to the raw diary feed.
We start with the broad overview:
How to read this graph: The upper panel shows a week's worth of recommended diaries. Each diary is a line that starts with a short blue segment and then goes red. The blue goes from the time of posting to the first appearance on the rec list. The red then shows the length of that diary's stay on the Rec list. Over the course of the week, there were 146 diaries, or about 20/day. The bottom panel shows the number of diaries posted each hour that subsequently made the Rec List. All times, by the way, are Pacific Daylight.
Looking at this graph, we see that most of the diaries on the Rec list are posted during the day, with a few in the wee hours of the morning (more on this later). Beyond that, there doesn't seem to be any magic time, with many daytime/evening hours seeing 1-2 newly posted Recommended diaries. Every day, though, has it's own ebb and flow.
This weekly overview graph is difficult to read, since it's hard to make out the individual diaries. So, let's look at two separate days, Wednesday and Saturday:
(On these graphs, the title of each diary is shown above its timeline.)
The first feature that jumps out about Wednesday is the big gap between 3 and 8 PM; on Wednesday, the Rec list was dominated by the morning and early afternoon postings, and nothing during the late afternoon/early evening block managed to break through. This day also saw a late-night diary make the list, posted just after midnight and making the list about 30 minutes later.
On Saturday, by contrast, diaries pop on to the list all day long, starting off with one champion that was posted really early and then spent almost 24 hours on the Rec list. Note, by the way, that it took almost 2 hours for that diary to move from the Recent to the Recommended list; at 4 AM, the diaries come slowly enough for a new diary to remain visible that long. Another interesting feature is at noon, where a diary drops off the list and apparently nothing replaces it. This means that a diary briefly popped on the list, displacing an older one, and then slid off in short order, with the displaced diary returning. Since we only track earliest and latest time on the list, this shows up as a temporary ninth recommended diary. In reality, one of the longer lines should have a gap in it. This doesn't happen all that often, but it's not unheard of. In general, on Saturday, over the course of the day, the Rec list turns over pretty steadily, with roughly 1 new diary every hour or so. This is very different from the peak/lull behavior that Wednesday saw.
Both sorts of behavior were seen on other days of the week, and days that showed "peak" times had those times vary wildly. For instance, on Sunday, 4 diaries ascended to the list in the space of one hour, 10-11 AM. So, for anyone looking for the magic time, that one golden instant when your magnum opus is guaranteed to make the Recommended list, I've got bad news. There is no such one time. There are times when a whole group of diaries moves up at once, but these times can only be seen after the fact, and they can't be predicted ahead of time.
To get a better sense of things, and to remove the daily swings and fluctuations, we can remove the day-of-week and just look at the number of diaries posted per hour-of-day that made the list:
Here we see that, with the exception of a lull around noon (probably a statistical fluke), the number of newly Recommended diaries varies smoothly across the course of the day. This isn't much use, however, without comparing with the total number of diaries posted:
(the data on this graph comes from a study done a few months back, looking at a quarter's worth of diaries, but with only the posting time available). Here, we see that the ratio of Rec'd/posted diaries, the likelihood of any given diary making the list, essentially doesn't vary over the course of a day.
So, the punchline:
There is no "best time" to post a diary to get it on the list.
Now, for a couple more graphs to close things out. Firstly, how long does it take for the typical diary to move from the Recent to the Rec list? That is, how long are those blue segments?
The typical Recommended diary first appears on the list within about 30 or 40 minutes of posting, but it's not unheard of for a diary to take upwards of 2 hours to make the leap.
The next question is how long do diaries spend on the list?
Here, there's a wide spread, with most of the diaries lasting for 0 to 5 hours, but a fair number lasting for up to 15 hours. Above that point, there's a real dropoff, with only a tiny number (3 in this sample) lasting a day or longer.
One last question that I was able to answer is "how complete is the Recommended tag?". I looked at the first three days of the set, 62 diaries, and found that 60 of them were tagged 'Recommended'. So, not perfect, but very very good.
The observant reader will note that I have not once given any sure-fire tips on how to get a diary on the list. That's because I'll share my secrets for the low low price of $50 there is no sure-fire way to get a diary on the Recommended list. Write about things that interest you, that you know about, and that you think the dKos community will be interested in. Listen to feedback from commenters, participate in the conversations in your (and other) diaries, and if nothing else, just keep trying.
-dms