Why is my library's total number of unique titles different on my Client Center Data Summary page and my Overlap Analysis report?

Specific calculations are used for displaying information about your collection on the Data Summary page, and these counts can be different from the numbers you will see represented in your library's Data Management page, Overlap Analysis, and Data on Demand.

The data that is displayed and calculated for the purposes for reporting and assessment tools can be affected by a variety of things, including:

• Whether the tool uses authority title information;

• At what point the data is calculated. In some cases, data that is displayed is reflective of real-time changes to your collection information in the Client Center; in other cases, the data does not display or is not used until it is updated via the Daily Profile Data Refresh; and

• The Display In services checkbox.

On the Data Summary page (accessed from the Client Center Home page, using the Data Summary link), Total Unique Titles refers to the total number of titles in your library's collection. It does not recognize two authority alternate titles as one title; instead, every variation of a title is counted as a separate title. It is simply the Total Holdings list with all exact-duplicate titles removed:

On your Overlap Analysis report (accessed from the Client Center Home page by clicking Overlap Analysis), Title Unique is the number of titles with unique access points (titles available from only one of your databases). Holding Unique refers to the number of journals and e-books available in more than one database, but without overlapping coverage dates. Total Unique then refers to the sum of Title Unique and Holding Unique:

Also: Titles being compared in Overlap Analysis have been normalized to the authority titles. Alternate titles and other title variations have been mapped to the corresponding authority title.

The data used in Overlap Analysis is updated daily, not in real time. Information on the Data Summary and Data Management pages is updated in real time.

See also:

• Data Summary

• Overlap Analysis

• Data on Demand

• Resource Status vs. Visibility in Various Serials Solutions Services

• Total Holdings Number on Data Summary Page vs. Data Management Page