Directory Last Edited Enquiry

My apologies if this has been asked before, but after noticing a selection of directory sections 'Last Edited' timestamps at the bottom of the page being upwards of 4 months old, what would be considered the average time that it takes for an Editor to make modifications to particular sections?

I ask this because the directory I have submitted to, the 'Last Edited' timestamp reads somewhere back in early July - while this is approximately 4 months ago, is this considered 'the norm' and expected time it takes between updates?

Or is the Editor of that particular directory section simply not taking the time to make more regular updates, therefore high quality sites looking to be included are having to wait longer?

Any insight into these enquiries is much appreciated.

1. There is no reliable way to predict when a given category will be visited by an editor.

2. What an editor does visit a given category, there are any number of actions that can be taken that do not result in the datestamp changing.

3. Additionally, the category itself plays a role: some categories are updated almost daily, others can easily be more that a year between updates. That's just how it is, since some categories are exceptionally stable and some are a hub of activity.

Well, we've got about 600,000 categories, and we have, say, 3000-6000 edits a day. There is perhaps a slight tendancy for edits to be clustered, which would raise the average; on the other hand, sometimes a category is worked hard -- perhaps dozens of site reviews -- without actually finding any reason to modify the category. So the time between bursts of editor activity is lower than the time between category modifications. Both of the last effects are hard to quantify, but probably small in comparision to the margin of error in the figure for number of daily edits.

Do the math -- thus much is not above sixth-grade arithmetic level, and gives a reasonable first-order approximation.

But you're actually seeing is a different number -- over all categories, the average time since the site has last been edited, which is actually somewhere between half 50% and 100% of the "average time between bursts of editor activity" (proof left as an exercise for the student!)

And, of course, since there are many good reasons why editor activity both is and ought to be very unevenly distributed, nobody has ever bothered to look at what that distribution actually IS.

Also, the 'last update' information does not permeate upwards through the directory. If the category you're looking at has subcategories, these may have more recent 'last updates'. I'd expect that sites could be reviewed in one category but judged better listed elsewhere, thereby not affecting 'last update' where submitted, rather only in category where placed.