Access statistics to SBN catalogue

SBN can be consulted in two different modalities corresponding to two client-server protocols: HTTP and Z39.50. Due to various technical reasons, SBN catalogue web interfaces can access bibliographic records through dedicated Z39.50 components.
These two protocols greatly differ from one another under many aspects, because Z39.50, unlike HTTP, was expressly conceived for the searching and retrieving of bibliographical records. For this reason, in order to assess the use of web interfaces carried out by users, it is better to record access at Z39.50 level rather than at HTTP level. In particular, at Z39.50 level can be tracked:
  • how many searches were performed;
  • how many times a particular search channel was used (title, author, etc...);
  • how many logical operators were used to combine together different search channels;
  • how many searches failed to produce results due to the lack of bibliographic records matching the search parameters;
  • how many records were returned for each search;
  • how and how much the indexes were used (byauthor, title, etc.);
  • how many bibliographic records returned in a search were actually viewed  by the user, and in which formats.
Much additional information is regularly recorded and organized in a special database available at
Several levels of detail are available for each web interface.

Data on HTTP access only is available at It is important to know that, due to the characteristics of the HTTP protocol, great attention must be paid to assessing this data with reference to the applying of the SBN protocol, for which the only truly reliable source are the Z39.50 statistics above explained.