Frequency
distributions

Analyzing
single
variables

Presenting univariate
data

Measures of
central
tendency

Measures of
variability

Standard
deviation and
the normal distribution

Computer
analysis
reminder

Aids

Computer analysis reminder

Before ending this chapter, we want to emphasize again the value of doing analyzes with the aid of a statistical analysis package. Although we used only small samples to illustrate how to do univariate analyses, you have seen the kinds of calculations that are required. Imagine the amount of tedious work involved when a large sample is used or when a number of variables are analyzed. With larger samples, calculation of the X and X ² values requires many mathematical operations. Also, with more hand calculations, there is a greater risk of making errors.   Other techniques of statistical analysis, which are described in the following chapters, require even more calculations. Computer-based analysis eliminates tedious calculations and the possibility of mathematical errors. Therefore, we suggest you check to see if your university or another organization has a statistical analysis package and that you learn how to use it. Once you complete analysis of data with the aid of a computer, believe us, you will never want to be without such assistance.

Aids

Internet resources

In addition to the sites mentioned previously in this chapter, we call your attention to the following sites that provide additional information and guidance about statistical operations.

PEPI v3.01, a software package designed for use in planning and structuring analyses in the health field, although it can be used for other areas as well; interactive and described as "easy to use"

Electronic Textbook StatSoft, this complete electronic statistics textbook can be downloaded for quick access on a local hard drive; part one provides an overview of elementary concepts in statistics; subsequent sections cover a wide variety of analysis methods

Statistics and Design provides brief descriptions of and links to sites containing information and guidance for analyzing data

We have introduced a number of statistical terms in this chapter. You will find short definitions of each in the Glossary. Other Web sites provide more extensive definitions of statistical terms, provide a conceptual basis for understanding them, and show how to calculate them. We refer you to the following sites:

Internet Glossary of Statistical Terms provides definitions of a wide range of statistical concepts and terms

Statistics Glossary provides definitions of terms used in hypothesis testing, illustrates steps involved, and shows how to interpret the results of hypothesis tests; provides links to Web sites that perform a wide range of statistical calculations