Measures of maximum load in PINES 1


I was curious about how many circulations PINES had on the biggest day on record. And that led to our asking: which hour and which minute had the most circs?

Maximum circs by DAY:
96,326 – May 29, 2007

Maximum circs by HOUR:
11,305 – May 29, 2007, 11 AM

Maximum circs by MINUTE:
548 – May 2, 2007, 9:21 AM

I understand that the day after Memorial Day in 2007 is remembered as a very busy day for reasons that are clear.

For a bit of perspective, the FY 2005 NCES/NCLIS data for all US public libraries give the following annual figures for total circulations by library:

Q3 (third quartile–the libraries above this number are in the top 25%):
144,663

Q2 (median–the middle value):
43,912

Q1 (libraries below this number are the bottom 25%):
13,113

The arithmetic mean is 229,685.

That maximum number of circs for PINES for one day is greater than the median annual value for all public libraries.

Why is the mean so much higher than the middle value? Because the distribution of all these numbers is highly skewed–in the Statistical sense. And that fascinating topic can be the subject for compelling blog post at another time.

Bob Molyneux


One thought on “Measures of maximum load in PINES

  • cj

    For the data dashboard junkies, I would pay money (based on a librarian’s salary) to see real-time (or close to it) updates to this type of stuff – basically if a visualization module could be built out that shows “most popular” categories by topic, author, etc., the PINES system is large enough that could be really interesting. Then add in YTD stats on circs and such – sorta like a MRTG-like data grapher for circulation “packets”.

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