Page 61 - Statistics for Dummies

Chapter 4: Tools of the Trade

In making conclusions, the researcher has to be aware that every study has
limits and that — because the chance for error always exists — the results
could be wrong. A numerical value can be reported that tells others how confi-
dent the researcher is about the results and how accurate these results are
expected to be. (See Chapter 12 for more information on margin of error.)
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 one candidate but women favor the opponent, the next
questions may 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,
organizing and summarizing the information, doing an analysis, drawing con-
clusions, discussing limitations, and, finally, designing the next study in order
to answer new questions that arise. Statistics is more than just numbers — it’s 45
a process.
Grabbing Some Basic Statistical Jargon
Every trade has a basic set of tools, and statistics is no different. If you think
about the statistical process as a series of stages that you go through to get
from question to answer, you may guess that at each stage you’ll find a group
of tools and a set of terms (or jargon) to go along with it. Now if the hair is
beginning to stand up on the back of your neck, don’t worry. No one is asking
you to become a statistics expert and plunge into the heavy-duty stuff, or to
turn into a statistics nerd who uses this jargon all the time. Hey, you don’t
even have to carry a calculator and pocket protector in your shirt pocket
(because statisticians really don’t do that; it’s just an urban myth).
But as the world becomes more numbers-conscious, statistical terms are
thrown around more in the media and in the workplace, so knowing what the
language really means can give you a leg up. Also, if you’re reading this book
because you want to find out more about how to calculate some statistics,
understanding basic jargon is your first step. So, in this section, you get a
taste of statistical jargon; I send you to the appropriate chapters elsewhere
in the book to get details.
Data

Data are the actual pieces of information that you collect through your study.
For example, I asked five of my friends how many pets they own, and the

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