Page contents:
Usage Statistics
Use by specified UK academic institutions
You can request a graph and table showing an annual summary of Copac use for any .ac.uk address. Enter the address into the box below, choose the required year, then select the 'Get stats' button. You can then download the usage figures as a .csv file for loading into a spreadsheet.
A couple of things to be aware of:
- Use by members of an institution will be an underestimate as it excludes those many academic users who access Copac from home.
- In a few cases users from a single institution access Copac with two different addresses and you need to search for these separately, eg. plym.ac.uk and plymouth.ac.uk
General use summary - 1997 onward
The graph below illustrates usage of Copac from 1997 onward. It includes total usage as well as a breakdown by interface, ie. Text (telnet), Web (including OpenURL access), Z39.50, and the experimental Copac v3 interface. The figures before and after the new interface release in August 2009 are not directly comparable
The usage figures are given in terms of sessions, each session may contain multiple searches. The graph also includes the number of sessions being blocked from the Karlsruhe Virtual Catalog for a short period to mitigate response time problems arising from high usage levels. [see below for details of blocked sessions].
Text summary of graph
available
Notes on the figures:
October 2009
A problem with the database software resulted in two separate occasions when the service was unavailable, lasting c. 3 hours each time. This will have resulted in a reduction in usage.
New interface release August 2009
The release of the new Copac interface in early August 2009 involved major changes to the way Copac works behind the scenes. One side-effect of this upgrade is a change in the way we can count search sessions.
In the past each time someone accessed Copac from the home page this started a new session, so a searcher could have several sessions in a single day. By contrast, an individual's search sessions are now potentially endless, so we are splitting them up by day. This means someone using Copac will now be counted as having one session on a specific day, no matter how many times they access Copac that day.
Consequently, figures before and after the new interface release are not directly comparable. Even though the total number of sessions for this September is higher than for last year, the number of sessions counted per individual per day will have declined in relation to the previous session count procedure.
May 2009
A hardware problem meant Copac was unavailable for c.3 days during 14-18 May, reducing May usage figures.
March 2009
A hardware problem meant Copac was unavailable for most of the week of 9th-13th March, losing nearly a quarter of the March usage.
September 2007
A hardware problem meant Copac was unavailable one weekend at the end of September. This will have affected the usage figures for September.
Copac V3 removed from use 28th March 2007
With the release of a new version of Copac on 28th March 2007 the experimental Copac V3 interface was removed from use as it was no longer needed for allowing searchers to try out the new interface developments. Thus there are no usage figures for Copac V3 from this date onwards.
November 2004 - loss of service for 48 hours
A power cut in the University of Manchester area caused a loss of service on November 15th 2004. When the power came back and the computers were restarted a hardware fault became apparent on the machine on which then Copac ran. This took some time to resolve and Copac was unavailable for c.48 hours. This will obviously impact on usage figures for November 2004.
Filtering of sessions 2003/4
High levels of use in October 2003 meant Copac users began to experience response-time problems. Because of the large number of sessions originating from the Karlsruhe Virtual Catalog access to Copac through this route was suspended for a day whilst the response time problem was assessed, resulting in the loss of an unknown number of sessions. After that access to Copac through the Karlsruhe interface was filtered, with a varying proportion of sessions being barred depending on how busy Copac was at any time. These barred sessions were recorded and are included in the usage statistics. Karlsruhe also started blocking access to Copac at busy periods, resulting in the loss of an unknown number of sessions. It is also possible that receiving a exclusion message may result in a general lowering of use through this route. Blocking of Karlsruhe sessions was removed in December 2004 when Copac moved to a new machine.
Loss of access from Karlsruhe 2002
In November 2002 a problem with the Karlsruhe Virtual Catalog meant Copac was not available through this route for some time. This caused a major reduction in access to Copac by Karlsruhe Virtual Catalog users, resulting in an overall drop in use this month. Use by all other groups of users, including UK academic, increased during this month.
Loss of system 2002
Loss of the system for several days during August 2000 reduced the usage figures for all interfaces.
Loss of session records 1998/1999
At the end of 1998 and start of 1999 an apparent drop in use is the result of the failure of the system logs for short periods. Loss of the system for several days during August 2000 reduced the usage figures for all interfaces.
The Interfaces
The Text and Web Interfaces were released in April 1996, early figures have been excluded to reduce the size of the graph. Unfortunately, the original Web interface did not permit the recording of sessions, we could only record individual searches. Thus the figures given in the graph for the old Web Interface are an estimate based on the relationship between numbers of sessions and searches found in the Web/Z39.50 gateway.
The Web/Z39.50 gateway was introduced as a replacement Web Interface in September 1998 and ran in parallel with the old Web Interface until the latter was withdrawn in July 1999. The Z39.50 Target was made available as we moved to a Z39.50 approach for all access to Copac, either via one of our own interfaces or via the user's own origin software. Owing to declining usage the Text Interface to Copac was removed when we moved to a new computer in December 2004.
