The reader must determine what biases are evident and how these may effect the content that is being presented. As an example, most of the information available on the Internet about nutritional supplements is provided by those who sell nutritional supplements. This information is then used to create personally prepared marketing materials aimed at the user. Some of this is done with forewarning and in other cases this is done more surreptitiously. The third criteria for evaluation concerns how old the material is.
People often assume that information provided on the Internet is the most current available.
Quality sites will date the origin of the page and also when it was last updated, so that readers can better evaluate the currency of information. The consumer of health information must most importantly attempt to evaluate the scientific validity of the health information. This may be difficult for the lay individual who has not been trained in research design or statistical methods, however general common sense can be helpful in determining if the material has logical origins. Having knowledge of how a study was conducted is crucial in determining if information and recommendations are valid. What was the sample size of the study and are the conclusions consistent with the methodology.