[MUSIC] Different information sources are used in different ways in different disciplines. As an example, in medicine, if you were looking for information about the latest cutting edge developments, then you would probably go to a journal article. That would be a good place to start. But then if you were studying in the liberal arts, you might be more likely to go to a film or even a book to get the same information. Now if you compare that to say, a law student who needs to identify a primary key source within law, then they would be best off going to a piece of legislation or a law report. But then if you compare that to someone in public health, maybe they need to look at trends in population health, so they might be more inclined to go to a bureau of statistics and download a dataset from there to get that information. [MUSIC] Primary, secondary, and tertiary sources are actually different depending on the discipline that you're looking at. As an example, within law, a primary source would be a piece of legislation or case law, that would be considered the law, in a sense that it is the most authority of source that you would use. But if you were looking at another discipline, and I'm thinking of something like history, a primary source might be a source that's the closest to the event that actually happened. Whereas, a secondary source might be something that describes that event. There is a link between primary and secondary in different disciplines but the type of document that they would use might be quite different. And then if we go a step out and look at tertiary sources, they may be things that actually organize the primary or secondary sources in some way. Within a discipline, you may have different types of information that you use and you just use it in different ways. As an example, if you're a medical student, and maybe you need to find out a bit more about cancer, and you want to get some background information, you'd be more likely to go to a textbook. Because you'd be looking at established knowledge and that would give you an idea about the general context of research around cancer. But then, if you were going to write an essay, for example, where you needed to look at different opinions on a topic, maybe different types of treatment for cancer. Then you might want to look at a journal article because that's where experts in the field would be debating these things back and forth with different journal articles. Increasingly, as well you might find that information on academic social networking sites where a lot of these debates are happening, as well. Knowing whether a source is appropriate to use, for whatever your purposes, one good starting point, I guess, is the lecturer that is providing the information to you. Often they will give you a reading list or they might give you some key references to look at if you are doing an assignment, and that can often be a good starting point for you. They might even suggest a textbook. You might start by looking at the types of sources that they're suggesting, journal articles or books or even datasets, depending on what type of assignment it is, and that is some way that you can start with. Once you get to that point, you might want to look at some of those sources as well and look at those types of sources that they refer to. [MUSIC]