Google allows you to search for numbers within a specific range, eg [stonewashed jeans $20..$30]. As indicated in the example the search is for a price range. That is also the origin of this operator. It was probably first developed for Google Catalogs (now a retired service). In the ordinary Google it is still available. Well hidden in the advanced search form.
The numrange operator works fine for many purposes.
[“mountain bike” $500..$800]
[“Russian revolution” 1900..1920]
[“Theobroma cacao” 2010..2014]
The last example hints on the retrieval of objects on cocoa between the (publication) years 2010 and 2014. Whereas the Russian revolution guesses the years the event took place.
It doesn’t work in Euros
So far it seems fine. But it doesn’t work for Euros.
[“mountain bike” €500..€800]
That probabaly has something to do with the character set. Nor for Pound Sterling [“mountain bike” £500..£800]. Albeit it doesn’t search for Pound sterling or Euros, it does return any number range.
Use three dots
The other problem with the numrange is that it doesn’t work for large figures. Search [water 988650..988700] fails. However, if you use three dots instead of the two dots, it works fine [water 988650…988700]
The other examples work with three dots as well as with two dots.
[“mountain bike” $500…$800]
[“Russian revolution” 1900…1920]
[“Theobroma cacao” 2010…2014]
So the quick conclusion is to use the tree dots rather than the two dots. Hattip for the three dots goes to @Henkvaness in his book Google Code.
Numrange operator in Google Scholar
In Google Scholar the numrange operator doesn’t work. Well that was my experience which I blogged yesterday in my Google Scholar blogpost. The numrange operator works for researchers searching for publications in the first place as a quick way to limit the results to a range of publication years. Google Scholar facilitates this trough the advanced search form or after a search action trough the facets in the search engine results page. But in the default Google Scholar search box the numrange doesn’t work for publication year ranges. Not with two dots [“Theobroma cacao” 2010..2014] nor with three dots [“Theobroma cacao” 2010…2014].
But Henk van Ess reacted on my slideshare “Google Scholar : Google for research” yesterday in the commments that the numrange work in Google Scholar. A little toying around. It works fine indeed for range that are not likely to be publication years. A search with three [“Theobroma cacao” 10…14] or two [“Theobroma cacao” 10..14] works indeed. But as soon as you come near a year range it doesn’t [“Theobroma cacao” 1800…1850].
If you want to search for year ranges in Google Scholar you have to do it through the advanced search form. Or use the more complicated url parameters as_ylo and as_yhi http://scholar.google.com/scholar?q=%22Theobroma%20cacao%22&as_ylo=1800&as_yhi=1850.
van Ess, H. 2009. De Google code. Amsterdam: Pearson Education. ISBN 9789043019088 136p.