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graph or chart can really help you keep the results in perspective.
    Checking your sources
    Check the source of the information; the best results are often published by a journal that's known by the experts in the field. For example, in the world of medical science, the Journal of the American Medical Association (JAMA), the New England Journal of Medicine, The Lancet , and the British Medical Journal are all among the reputable journals in which doctors publish results and read about new findings.
Tip 
When examining the results of any study, consider the source and question all of the studies that were conducted, not just those whose results were published in journals or appeared in advertisements. A conflict of interest on the part of researchers can lead to incorrect information.
    Counting on the sample size
    Sample size isn't everything, but it does count for a great deal in terms of surveys and studies. If the study is designed and conducted correctly, and if the participants are selected randomly (that is, with no bias; see Chapter 3 for more on random samples), sample size is an important factor in determining the accuracy and repeatability of the results. (See Chapters 16 and 17 for more information on designing and carrying out studies.)
    You may think that all studies are based on large numbers of participants. This is true for most surveys, but it isn't always true for other types of research, such as studies involving carefully controlled experiments. Experiments can be very time consuming; sometimes they take monthsor years to conduct in a variety of situations. Experimental studies can also be costly. Some experiments involve examining not people but products, such as computer chips or military equipment costing thousands or even millions of dollars. If the experiment involves destroying the product in the process of testing it, the cost of each experiment can be quite high. Because of the high cost of some types of research, some studies are based on a small number of participants or products. But fewer participants in a study (or fewer products tested) means less information overall, so studies with small numbers of participants (or products) in general are less accurate than similar studies with larger sample sizes.
    Most researchers try to include the largest sample size they can afford, and they balance the cost of the sample size with the need for accuracy. Sometimes, though, people are just lazy and don't want to bother with a large enough sample. Sometimes, those researchers don't really understand the ramifications of having a small sample. And some folks hope you won't understand the importance of sample size, but now you do.
HEADS UP 
The worst examples of woefully inadequate sample size I've seen are TV ads where the sample size is only one. Usually, these commercials present what look like experiments to try to persuade the viewers that one product is superior to another. You've probably seen the TV commercial pitting one paper towel brand against another, where one piece of each type of paper towel is used to try to absorb the same amount of red juice. These examples may sound silly, but anyone can easily fall into the trap of drawing conclusions based on a sample size of one. (Have you ever told someone not to buy a product because you had a bad experience with it?) Remember that an anecdote (or story) is really a study with a sample size of only one.
REMEMBER 
Check the sample size to be sure the researchers have enough information on which to base their results. The margin of error (see Chapter 10 ) also gives you an idea of the sample size, because a small margin of error most likely means that a large sample was used.
    Your doctor's time: Quantity or quality?
    Headlines are the media's bread and butter, but headlines can also be misleading. Oftentimes, the headlines are more grandiose than the "real" information, especially when the stories involve statistics and the studies that generated