When are our libraries used?

To help inform the second part of the library consultation, we have generated a series of heatmaps around library usage in South Gloucestershire to identify ebbs and flows in book borrowing. The aim of this was to add to the discussion around the question “if cuts were made, are there any times where that would cause minimal disruption?”.

The heatmaps are based on book borrowing data from the period of March 2015 – March 2016, and are broken down into two types:

  • usage by hour – the total books borrowed over the course of the year are mapped to the day of the week and hour. Colours range from yellow to blue by the number of books borrowed.
  • usage by day – the books borrowed are mapped to the day of the year, allowing general month-by-month trends to be visible. Colours range from yellow to red by quantile – “considering usage across days, which 10% of the distribution did this day fit into?”

In addition, we have added these charts to the library pages, so that readers can examine their specific library, such as that for Hanham.

What we found through this was that in general, library usage is pretty constant throughout the year, with very heavy use during the summer holidays. There is not much in the way of scope for cutbacks without a considerable service interruption.

Looking at the service through this lens of book borrowing runs the risk of distorting the value of low periods:

  • people may come into the library at quieter times to study
  • librarians may use quieter times to prepare for school groups etc.

Optimising a service to run at maximum capacity, reduces its ability to adapt to changing demands. Consider the analogy of a busy airport that has to cancel flights at the first sign of snow because 5 minute delays cause backlog in the entire flight schedule for the day. A bit of slack is good.