Did you mean?

Sadly many OPACs offer the user a very limited set of features. Where in general the internet becomes more and more user-friendly and interactive (a.k.a. Web 2.0), many OPAC providers seem to lag behind and be content with their eighties-style usability, disregarding the expectations of the present-day internet user.

One such feature that helps to greatly improve on the usability of your OPAC is what's known as a "Did you mean...?" function, as popularized by Google. When a user does not get any (or a small number of) results for her query, the OPAC responds by suggesting alternative queries that are similar, but that do result in more hits from your catalog. This similarity is often determined by the use of the information-theoretic Levenshtein distance : an expression of how close one string is to another.

OpacOnline boasts such a "Did you mean.. ?" function. Whether it is enabled for your OPAC, and what is the results threshold to invoke it (by default, when your query returns no results), is of course fully configurable; as is the number of suggestions that are displayed.

The suggestions are links that the user can simply click to execute the suggested query, with all other user-set parameters such as language selection preserved.

Below you can see OpacOnline's "Did you mean.. ?" feaure in action. The query "ekma" having produced no results in the NiZA library catalog, the 5 suggestions with the highest Levenshtein ranking are shown and presented to the user as alternative queries.