Monday, April 25, 2005

Proximity Operators Correction

I’m making it correction to last week’s post “Proximity Operators” (April 15), specifically about the Ovid ‘adjacency operator’.

Even as I wrote about the adjacency n (adjn) operator, I was fairly certain that it was wrong and against my better judgment, I went ahead with the post.

As I write each entry, I check and double check to make certain that what I say is correct. And I discovered a discrepancy between the information published in Ovid’s Online MEDLINE Field Guide and how I have been teaching and utilizing the adjacency operator for years. I checked Ovid’s Advanced Searching printed brochure and it corroborated what I believed to be true. What to do? I felt that because the online Field Guide was more recent information that I would believe that and I posted the information on the ‘adjacency operator’. At the same time, I wrote to Ovid to say that I thought the Online Field Guide was incorrect and asked for a definitive answer on the adjacency n operator. I heard from Ovid Support on Friday, April 22. And, yes, the Online Field Guide is incorrect.

Here’s what I originally reported about the ‘adjn’ operator:

blood adj2 clot$ - retrieves records that contain both terms, in order, with two words between

Now, here’s the correct information:

blood adj2 clot$ - retrieves records that contain both terms, in any order, with two words between

And here’s why it’s so important – because when you’re looking for a phrase or for words, you want to be able to compensate for the order in which the phrase or words were used. Keep in mind that the closer the words are together the tighter the relationship between them; the further they are apart, the looser the relationship. So when using adjn, try to keep the n somewhere between 2 and 7 – the higher it is, the greater the likelihood of retrieving irrelevant results.

I’ve made the correction to the original post.


Post a Comment

<< Home