In this video, we're going to discuss Boolean operators.
What a Boolean operator is, is a fancy term for the way in which you combine terms together to build relationships.
There are only three Boolean operators: And, Or, and Not.
For the purposes of this video, we're only going to concentrate on two, and that is And and Or.
Now when it comes to using these what you'll notice is that, when it comes to using AND,
you use And to combine concepts and to develop a relationship.
When using AND such as if you were doing Soda Pop AND Weight Gain what it will do is it
forces the database, or the articles you'll get back from a database search, will involve
both soda pop and weight gain.
If both of the terms are not either in the subject heading field or somewhere in the
citation, depending on how you've searched, those articles will not show up in your results.
And so AND is very important; it will give you a relationship.
Like in this instance, Soda Pop and Weight Gain would return to me articles that discuss
soda pop and how people gain weight, which then ensures that the articles you are getting
are applicable to your question.
Whereas when it comes to OR, what OR is used for is to combine synonyms or like-concepts
such as if you were doing the thing on Soda Pop and Weight Gain one of the things you
might be interested in looking at are all articles that deal with Coke or all articles that deal with Pepsi.
And then you might want to turn around and take those and combine them together to see
how they deal with weight gain.
OR will really help you to broaden your search or give you a lot of articles, but just because
it gives you a lot is not always useful unless you make a good relationship with AND afterwards.
When you use OR, keep in mind there doesn't have to be a relationship between Coke or Pepsi.
What it means is, the articles that you get back are either going to discuss Coke or Pepsi
but don't have to discuss both.
Now a lot of people when they look at this, they get a little concerned or confused about
where you use them.
The way to think about it is when you're setting up you're search - as I told you before - you're
going to group your search or block your search off into concepts.
Within a group, which is where you have your like-concepts, is where you're going to use OR.
When you want to take your groups and combine them together to develop a relationship, that's when you use AND.
Now going back to the example I had earlier where we discussed trying to help a patient
with their pain issues by using alternative therapies such as therapeutic touch or guided
imagery, you may end up with something that looks like this.
What you'll notice here is that, when it comes to fibromyalgia, when you search it, you may
do it as Fibromyalgia with a subject heading OR Chronic Fatigue Syndrome OR Fibromyalgia
as a keyword OR Chronic Fatigue Syndrome as a keyword.
What you're doing here is, all of these terms or related terms are different ways to approach the same condition.
The reason you see chronic fatigue syndrome here is when looking at the literature, many
times chronic fatigue syndrome and fibromyalgia are discussed as one and the same or are very closely related.
And so what I would do here is, I would order these all together to pull every article that
either had fibromyalgia as a subject heading or chronic fatigue syndrome as a subject heading
or has either of those terms as a keyword, therefore ensuring that I'm finding all of the articles.
And so the number of articles I'm going to get are pretty large.
I would do the same thing when it comes to Therapeutic Touch and Guided Imagery.
And then what you'll notice I'll do is, there'll be a large number for Fibromyalgia, a large
number for Therapeutic Touch, and a large number for Guided Imagery.
And then if I wanted to ensure that the articles I received discussed all three, I could put AND.
I could use the AND to bring them together, and that's how you use the AND and OR to develop
the relationships in order to ensure that you're getting everything that you need.
Now one of the things you'll need to keep in mind - and this a little bit advanced but
I wanted to put it out there - is that in order to do a good search, especially in PubMed,
you many times have to do a combination of a subject heading and keyword search.
The reason you have to do this is that, in especially PubMed, there are articles in there
that have not had subject headings attached to them.
Most of the time they are the most recent articles, like say from the last month, and
so the only way that you can find them is not by using subject headings but by using
keywords, which takes me back to when we were talking earlier about finding those alternative
concepts or alternative ways of describing things.
Those could be your keywords like I've done here to ensure that you're getting everything.
And that is how you use the Boolean operators or try to make relationships between the concepts
when you're doing a search.