Finding Materials by Call Number

When you find a book (or journal, videorecording, sound recording, or other item) in OneSearch, it will indicate a Call Number, a Location, and a Status:  

catalog record

If the Status is “Available,” the item should be in its proper home in the library. If it is “Currently Out,” someone else has checked it out. You can “Make a Request” to recall the book (it should be available in a week or so), or look in OneSearch to see if Trinity or Conn College has an available copy you can request (their copy should be available in a couple of days).  

The Location indicates the general area where it is – Olin Stacks, Olin Reference, Music Stacks, Science Library, Government Documents, Electronic Book, etc. If it is an online item, there will be a link to access the content. For physical items in the library, consult the Library Floor Plans map to find where the Location is located. Some Locations (such as Special Collections & Archives) are in closed areas so you will need to ask a library staff member for assistance.

The Call Number specifies where in the Location the item can be found.  The Library Floor Plans map indicates which call number ranges are where.  

Most call numbers are from the Library of Congress Classification System. Letters and numbers are assigned by subject, so books on the same topics are shelved together. (The list of Library of Congress Call Number Locations indicates where subjects are shelved.) They are arranged alphabetically and numerically, but some numbers are treated as whole numbers and some are decimals. So, to take the example above:

     LD 5901   .W 32   P 683   2015

L is for all books on Education. LD is where books on specific educational institutions, such as Wesleyan University, are placed. On the shelf, the categories are placed alphabetically:

     L –> LA –> LB –> LD

5901 is treated as a whole number. So if you find LD 594, you need to go further through the LD section

     LD 594 –> LD 1000 –> LD 5901

.W 32 – this number is treated as a decimal, so it comes after .W 295 and before .W 6

     LD 5901 .W 295 –> LD 5901 .W 32 –> LD 5901 .W 6

P 683 is also treated as a decimal.

The last number – 2015 – is the publication date. If another edition is published later, it would likely have the same call number with a new date.


A few items have a different call number system.

To find Government Documents (in the ground level of Olin), consult the guide to SuDoc (government documents) Call Number Locations

To find Cutter books (some older books housed in the Science Library on the lower level), consult the guide to Cutter Call Number Locations