When choosing a web site, you want to think the same way a journalist investigating a source would. By asking questions about the site, using your critical thinking skills, and digging deeper into what the site is all about you help ensure that you are using good-quality, reliable information. That will prevent embarrassing mistakes in class, and get you in the habit for when you go into the working world when mistakes can be worse than embarrassing.
Ask yourself:
Who wrote this? Are they reliable?
What is the purpose of the site providing the data? Have they got an agenda? If so they might adjust the data to look good!!
When is this data from? Is it up-to-date?
Where is the data from? One way to look at this when you're online is to examine the web address to see what type of "domain" it is. If the address has a ".com" in it, it's a commercial site and may be just out to make money. Consider ".edu" (educational), ".gov" (US. government), or ".org" (nonprofit organization) sites instead.
Why choose this data over any other?