BIBSYS Ask: what you know, what you don’t

by

Consider the following. Perform a search in BIBSYS Ask’s “Advanced search” in the following way:

  1. create four search fields
  2. enter “cats”, “dogs”, “sheep” and “pigs” in each of the fields
  3. specify “and”, “or”, “not” before each field
  4. tick off “E-books” in materials

What did you just do? According to the search results page, you’ve searched for:

cats and dogs or sheep not pigs and material type = e-books

Unfortunately, that isn’t the case, what you’ve just searched for is rather more complex; click [Search], and choose “Special search” to view the CQL that was passed as the query, you’ll see this:

((((bd = “cats”) AND (bd = “dogs”)) OR (bd = “sheep”)) NOT (bd = “pigs”)) AND ((form = “n”) AND (innhold = “v”))

Two things to note here:

  1. the binding of the operators is done sequentially
  2. when selecting “E-books”, you’re selecting a specific form and content type

Point one is problematic because if you meant to search for results on (cats and (dogs or sheep)), then you’re doing it wrong. Point two is problematic because you’re having to rely on good cataloguing practice in imported records, to demonstrate that this isn’t so good try the following searches:

(form = “n”) AND (innhold = “v”)

(form = “n”) AND ((innhold = “v”) OR (innhold = “c”))

At the time of writing, these searches return the following numbers of results respectively:

197506

197910

This difference is due to the fact that the imported records don’t necessarily feature $b v in addition to $b c in MARC field 008. A simple thing, but nonetheless problematic since we believed we were searching for all e-books, not just monographs.

So, what do we know? For one, fielded search is a suspect idea, and must be used with caution because the logic that interprets your query typically binds your search terms in an undesirable way for non-trivial searches. Secondly, getting what you asked for isn’t always too easy when you don’t know what you’ve actually asked for. Thirdly, if you’re performing complex searches, CQL in special search is the only way to go. And fourthly, none of this will matter because most people will sensibly look for a particular book in the library catalogue rather than trying to search in this way.


%d bloggers like this: