Statistics for Dummies Read Online Free PDF Page A

problems, you'll be well on your way to becoming more confident about statistics, ready to tackle the numbers explosion!

Taking Control: So Many Numbers, So Little Time
    Statistics end up on your TV and in your newspaper as a result of a process. First, the researchers who study an issue generate results; this group of people is composed of pollsters, doctors, marketing researchers, government researchers, and other scientists. They are considered the original sources of the statistical information. After they get their results, these researchers want to tell people about it, so they typically put out either a press release or a journal article. Enter the journalists, who are considered the media source of the information. Journalists hunt for interesting press releases, sort through the journals, and basically search for the next headline. When reporters complete their stories, statistics are sent out to the public. This can happen through a variety of media: TV, newspaper, magazines, Web sites, newsletters, and so on. Now the information is ready to be taken in by thethird group, the consumers of the information (you!). You and other consumers of information are the ones faced with the task of listening to and reading the information, sorting through it, and making decisions about it. And as you may have guessed, at any stage in the process of doing research, communicating results, or consuming information, errors can take place, either unintentionally or by design.
     

Detecting Errors, Exaggerations, and Just Plain Lies
    Statistics can go wrong for many different reasons. First, a simple, honest error could have taken place. This can happen to anyone, right?
    Other times, the error is a little more than a simple, honest mistake. In the heat of the moment, because someone feels strongly about a cause and because the numbers don't quite bear out the point that the researcher wants to make, statistics get tweaked, or, more commonly, they get exaggerated, either in terms of their values or in the way they're represented and discussed.
    Finally, you may encounter situations in which the numbers have been completely fabricated and could not be repeatable by anyone because the results never happened. This is the worst-case scenario, and it does happen in the real world.
    This section gives you tips to help you spot errors, exaggerations, and lies, along with some examples of each type of error that you, as an information consumer, may encounter.
    Checking the math
    The first thing you want to do when you come upon a statistic or the result of a statistical study is to ask the question, "Is this number correct?" Don't assume that it is! You may be surprised at the number of simple arithmetic errors that occur when statistics are collected, summarized, reported, or interpreted. Keep in mind that another type of error is an error of omission — information that is missing that would have made a big difference in terms of getting a handle on the real story behind the numbers. That makes the issue of correctness difficult to address, because you're lacking information to go on.
Tip 
To spot arithmetic errors or omissions in statistics:
Check to be sure everything adds up. In other words, do the percents in the pie chart add to 100? Do the number of people in each category add up to the total number surveyed?
Double check even the most basic of calculations.
Always look for a total, so that you can put the results into proper perspective. Ignore results based on tiny sample sizes.
    Microwaving just doesn't add up
    Many statistics break results down into groups, showing the percentage of people in each group who responded in a certain way regarding a particular question or demographic factor (such as age, gender, and so on). That's an effective way to report statistics, as long as all the percentages add up to 100%.
    For example, USA Today reported the results of an opinion research study done for Tupperware regarding microwaving