Knowing the source type (book, periodical, website) and whether it is more popular or scholarly are good ways to evaluate a source from the outside. But you also have to know how to evaluate a source from the inside. Librarians and internet educators have developed many catchy and quirky acronyms for evaluating websites. There is, for instance, CARS (Creditability, Accuracy, Reasonableness, Support), PACAC (Purpose, Authority, Content, Accuracy, Currency), and CRAAP (Currency, Relevance, Authority, Accuracy, Purpose).
What it boils down to is: who wrote the site and why? Is the information on it accurate and objective and does it suit your purpose (i.e. is it relevant to your thesis)?
These same criteria often apply to all sources you may find and consider using, even academic sources from library databases. But it is especially important to consider the source when you find it on the open web because websites often lack many of the editorial processes traditional sources have in place, such as peer review. In other words since, on the web "anybody can write anything" you have to be especially careful.
Let’s look at a few examples.
Say your research topic is on global warming. You’re not sure yet how you want to develop and narrow this down, but you know you’ll need some “hard facts” to start with. What do the experts and the scientists say about the science behind global warming. So you do some simple Googling to get started...
Follow along with the presentation below. The two sites we'll look at are: