Statistics: More than Just Numbers

Most statisticians don't want statistics to be thought of as "just statistics." While the rest of the world views them as such, statisticians don't think of themselves as number crunchers; more often, they think of themselves as the keepers of the scientific method. (Of course, statisticians depend on experts in other fields to supply the interesting questions, because man cannot live by statistics alone.) The scientific method (asking questions, doing studies, collecting evidence, analyzing that evidence, and making conclusions) is something you may have come across before, but you may also be wondering what this method has to do with statistics.

All research starts with a question, such as:

• Is it possible to drink too much water?

• What's the cost of living in San Francisco?

• Who will win the next presidential election?

• Do herbs really help maintain good health?

• Will my favorite TV show get renewed for next year?

None of these questions asks anything directly about numbers. Yet each question requires the use of data and statistical processes to come up with the answer.

Suppose a researcher wants to determine who will win the next U.S. presidential election. To answer this question with confidence, the researcher has to follow several steps:

1. Determine the group of people to be studied.

In this case, the researcher would use registered voters who plan to vote in the next election.

2. Collect the data.

This step is a challenge, because you can't go out and ask every person in the United States whether they plan to vote, and if so, for whom they plan to vote. Beyond that, suppose someone says, "Yes, I plan to vote." Will that person really vote come Election Day? And will that same person tell you for whom he or she actually plans to vote? And what if that person changes his or her mind later on and votes for a different candidate?

3. Organize, summarize, and analyze the data.

After the researcher has gone out and gotten the data that she needs, getting it organized, summarized, and analyzed helps the researcher answer her question. This is what most people recognize as the business of statistics.

4. Take all the data summaries, the charts and graphs, and the analyses, and draw conclusions from them to try to answer the researcher's original question.

Of course, the researcher will not be able to have 100% confidence that her answer is correct, because not every person in the United States was asked. But she can get an answer that she can be nearly 100% sure is the correct answer. In fact, with a sample of about 2,500 people who are selected in a fair and unbiased way (so that each member of the population has an equal chance of being selected), the researcher can get accurate results, within plus or minus 2.5% (that is, if all of the steps in the research process are done correctly).

In making conclusions, the researcher has to be aware that every study has limits, and that — because there is always a chance for error — the results could be wrong. A numerical value can be reported that tells others how confident the researcher is about the results, and how accurate these results are expected to be.

After the research is done and the question has been answered, the results typically lead to even more questions and even more research. For example, if men appear to favor Miss Calculation but women favor her opponent, the next questions could be, "Who goes to the polls more often on Election Day — men or women — and what factors determine whether they will vote?"

The field of statistics is really the business of using the scientific method to answer research questions about the world. Statistical methods are involved in every step of a good study, from designing the research to collecting the data to organizing and summarizing the information to doing an analysis, drawing conclusions, discussing limitations and, finally, to designing the next study in order to answer new questions that arise. Statistics is more than just a number; it's a process!