 Hi, my name is Alex, I'm a librarian at the University of Alabama, and in this tutorial I'm going to show you how to use PubMed's Mesh Terminology system in order to become a more effective searcher. Mesh stands for the Medical Subject Headings and are what's called a Controlled Vocabulary System. During this tutorial, I'll try to avoid too much library jargon and instead focus on why you might use Mesh Terminology for searching and how you might do so. Using Mesh Terminology is the best way of searching for articles on PubMed. Keywords searching can be useful and effective, but understanding Mesh Terminology is really the key to unlocking this database. You can find the Mesh database towards the bottom of PubMed's homepage. Now that we're here, we'll begin to explain what Mesh Terminology is. The Mesh system is how PubMed is organized. Each article that is indexed in PubMed is assigned to various Mesh Terms and Headings that describe the contents of the article. Let's get a sense of what I'm talking about. To start with, I'll just run a normal keyword search on PubMed. We'll get back to the Mesh database later. When you click on an article, you'll always see Mesh Terms on the right hand side of the screen. PubMed has assigned this article about type 2 diabetes a number of Mesh Terms that describe the contents of the article. In this case, it's mostly about type 2 diabetes, but each of these has a subcategory, diagnosis, drug therapy, etc. It's also telling you that it's about humans and disease management, and so on. So what does this have to do with searching PubMed? Well, a couple of things. One, you can actually click on any of these Mesh Terms. In that sense, even though this is a bit overly simplistic, they're almost like hashtags. If I click on the first Mesh Term, what I find are around 10,000 articles. I know that every one of these 10,000 articles has been tagged with the Mesh Term type 2 diabetes slash diagnosis. Because I know that, I know that all 10,000 of these articles are at least partially about that concept. In that sense, this is more reliable and precise than a keyword search. No matter how good your keyword search is, you're always going to get some articles that are only borderline relevant and some articles that just aren't relevant at all. And that's really just the beginning of why Mesh Terminology is important for searching PubMed. Mesh Terminology tells you what terms PubMed wants you to use when searching. A quick example is running a keyword search for cancer. There's several problems with this search. One, it's just too broad. You'd most likely want to search for a type of cancer combined with some other keywords. But the other problem is that cancer is not the only keyword you need to look for. For example, the more scientific term for cancer is neoplasms. A search for that brings back entirely different articles that you'd miss if you just searched for cancer. We talked in a previous tutorial about the Boolean operator OR, which is good for related terms. You could use OR to connect multiple terms like cancer or neoplasms or tumors, but you'd be better off just using PubMed's Mesh Terminology. So we'll go back to the Mesh database and see what terms PubMed wants us to use. What you'll find is that the primary Mesh term is neoplasms. For lung cancer, it would be lung neoplasms and so on. I can build a search right from here using PubMed's search builder. I'll add this to the search builder and at this point, I could either just add a keyword or I could use another Mesh term. For the purposes of this tutorial, I'll use another Mesh term. I want to look at nutritional therapy for lung cancer, so I'll do a Mesh search for that. Add that to the search builder and then search PubMed. What we have is a very precise search, at least more precise than a keyword search for these two concepts. There's a lot to cover when it comes to Mesh searching on PubMed, but we'll save the rest of it for another tutorial. Hopefully you now have a decent foundation for using Mesh Terminology. And remember, if you have a question, just ask a librarian.