[OPEN-ILS-GENERAL] Truncation curiosity

[Dan Scott]

Truncation with the asterisk is a new feature in 2.0.

Stemming matches "teach" with "teaching" as a regular suffix "ing", but does not match "teacher" as "er" is not a recognized suffix by the stemming algorithm. The * forces matches against anything starting with "teach", and the high ratio of matches in the title makes the microform results more relevant. 

Mahria Lebow <mahria at gmail.com> wrote:

Hi there,

I was looking through some help documentation for end users when I stumbled onto a bit of a mystery.  Evergreen documentation seems to indicate that when users are searching the OPAC search terms are automatically stemmed (and some documentation specifically notes that truncation is not allowed).  However, the error message a user receives when they encounter null results for a search (in some builds, such as King County Public Library) offers this suggestion:

Truncation
		Words may be right-hand truncated using an asterisk. Use a single asterisk * to truncate from 1-5 characters. Use a double asterisk ** for open-ended truncation.

Regardless of the suggestion itself, curious things happen when one does use an asterisk in a keyword search.  Again, using the KCPL catalogue, a keyword search for teach pulls up 2570 results, the first being being eSerial Teach and second a magazine, Teaching pre K-8.  However, if someone was to throw in an asterisk (teach*), the number of results increases to 2770 and the first two results are now microforms, The exchange -- best teaching practices from around Ohio: teacher to teacher.

So, what function does an asterisk serve in an OPAC search?

Cheers,
Mahria 


		

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