The major responsibilities of occupational safety and health professionals are to identify
where problems exist and to develop interventions to solve those problems. The
problem-identification process requires the safety professional to determine what the
current situation is and compare it to what is acceptable. If the situation is unacceptable,
intervention is required. The safety professional must then determine if the intervention
is working. To meet these responsibilities, the safety professional must be
able to collect data, analyze them, draw conclusions from them, and communicate the
results to others.
This book provides the safety professional with the basic statistical and data analysis
techniques that can be used to address some of the problems that he or she will encounter
on a daily basis. It covers the data analysis process, from research design to data
collection, analysis, reaching of conclusions, and presentation of the findings. At the
end of each chapter, sample problems are provided to help users of this book learn to
apply the information presented. Solutions to most problems appear at the back of the
book.
Chapter 1 presents the more common terms and notation used in statistics. Proper
design of research hypotheses and studies is described, as well as the procedures one
should follow when selecting subjects for a study. A variety of sampling techniques are
discussed, along with examples of appropriate uses of these sampling techniques.
Chapter 2 provides, in detail, the concepts of probability and chance, the underlying
principles of statistical significance. Probability formulas are presented for simple,
joint, compound, and conditional events. Binomial and Poisson probabilities that
the safety professional may encounter in various statistical applications are also presented.
The different distributions that the results of statistical tests may assume are discussed
in Chapter 3, as well as the procedures for constructing histograms and frequency
polygons.
Chapters 4 through 8 discuss descriptive statistics, inferential statistics, and nonparametric
statistics. These chapters discuss hypotheses testing using the various procedures
and formulas, and also discuss determining the significance of the results of the
test or procedure.