In order to fully evaluate a resource, you should look beyond the information provided within that particular resource. So, for instance, if you are evaluating a book there will most likely be information about the author provided within the book. On the other hand, you will rarely information included about the publisher within the book beyond where they are located.
Where might you look to find more information about an author? Where might you look to find more information about a publisher? Why is it important to look beyond an information resource to evaluate the author and the source?