Our default search operator is AND. Last time I looked, about 82% of
users used AND, 13% used exact phrase matching, and the remaining 5%
were about evenly split between OR and proximity matching.

A casual scan of the search terms people use suggests that multi-term
searches are usually in the form of names (like "Louis Riel") or
concepts ("Murder in the Yukon", "History of Hudson bay company"). I
don't think I've ever noticed anyone searching using several synonyms,
where OR searching might actually be useful.

William Wueppelmann
Canadiana.org
(formerly Canadian Institute for Historical Microreproductions)
http://www.canadiana.org


Ross Singer wrote:
> What do you think is more appropriate (and intuitive) for a search
> engine if the user gives no boolean, "and" or "or"?
>
> I guess my question is, assuming it's a keyword search, and the user
> types in "institute paper science", would it be more appropriate to
> default to "institute AND paper AND science" or "institute OR paper OR
> science".
>
> I'm just sort of curious what other people's take on this might be.
>
> Thanks,
> -Ross.
>