Is it necessary to leave WebDewey to view LCSH authority records? 

No, not for subject headings that have been mapped to Dewey numbers.  Tens of thousands of LC subject headings have been mapped to Dewey numbers in WebDewey.  They are mapped in two ways: intellectually, by the Dewey editorial staff, and statistically, by means of an algorithm that is applied to WorldCat (the OCLC online union catalog) to determine the co-occurrence of DDC numbers and LCSH.  You can easily follow links from these mapped subject headings to view the authority records in a separate window without leaving WebDewey.  For example, you have a book for which you have found cataloging copy with the LCSH "Evolutionary computation" but no Dewey number.  You are not familiar with the concept.  In WebDewey you search for "evolutionary computation" and get one result, which appears in a full record display: 006.32 Neural nets (Neural networks).  In the Terms part of the display for 006.32, under LC Subject Headings, you click Evolutionary computation.  A new window appears to display the authority record.  In the authority record you find a definition for evolutionary computation in a MARC 670 field (Source Data Found).  You also find the broader-term reference to Neural networks (Computer science) (MARC tag 550 $w g).  You click that reference to view the authority record for Neural networks (Computer science).  When you evaluate the information you have found, you conclude that "Evolutionary computation" is the right LCSH for the book in hand, and 006.32 is the correct Dewey number. 

Last revised: 31 January 2004