Assessing if information fits your question
When you are checking the relevance of the results of your search, two aspects are important to monitor:
1. Does the result fit with the information need that you have? For instance: someone who is making a presentation for high school students, doesn't really need a dissertation as an information source. A dissertation will word the information on a different level than the high school students would understand. A different example: you don't want to find a VHS tape if you know you only have access to a DVD player.
2. Is the source reliable? How objective does the result look? Did an expert write it? Does it have references? If so, do those references come to the same conclusion?
To make a good selection from the results, you will have to be able to judge the quality and relevance of the results. There are different reasons why some sources are a good choice, and others aren't. An article might be biased because the writer is writing from a certain perspective, religion or commercial advantage, etc.
That's why it is important to use various results and to compare the conclusions.
To assess a source, ask yourself the following questions:
Is the source mentioned in other publications? (You can easily check this in Google Scholar, by clicking on Cited By)
Was an editorial used? Is the editorial knowledgeable on the subject?
Everybody can be an author on the internet, and sell their opinion as facts. There is no editorial or commission that checks if information is correct, or objective. The line between commercial information (propeganda) and fact is also vague. You have to constantly ask yourself if the information is reliable enough, and how big a role you want to give this type of information in your assignment.
The CRAP test can help in evaluating a website source.