Evaluating statistical information is crucial. There are two ways in which you must evaluate statistical information:
You will need to evaluate every statistic that you use on these two points.
How can you determine if a statistical source is reliable? Evaluating the source of compiled statistics is crucial. Answering these questions will help you to evaluate how reliable the data is for a particular source. Be sure to review all sources for: Authenticity
Reputability and Bias
Validity
Accuracy

Are there sources that are always reliable?
How can you tell if a statistic is relevant to your research?
When selecting statistics, be sure they meet your needs in the following three areas:
Using Statistics or How do I read this table, anyway?
Statistical data can be complex to examine. There is often a lot of information contained in a statistical table, graph, or data set. There are some common elements that you should look for when examining a statistical source. This information will be critical to your evaluation of the source, as well as how you use the data for your research.
Every piece of information in a table or graph is important to the understanding of the statistics presented. Statistical tables and graphs pack a great deal of information into very little space.